A Passion for Petrocosmea

Petrocosmeas (and this blog!!!) in the News!!

2011-11-29T18:07:00.003-05:00

Finally!!! Petrocosmeas are in the news and getting the attention we all knew they deserved! I was delighted by an article in the RHS publication "The Plantsman" back in September that announced a new name for one of our most popular Pet species...the former Petrocosmea rosettifolia. The new, and proper name for this plant is Petrocosmea cryptica as described and published by Julian Shaw of the RHS. I am attaching a link to the article here:
www.rhs.org.uk/Plants/RHS-Publications/Journals/The-Plantsman/2011-Issues/September/Petrocosmea

Petrocosmea cryptica '#3' (formerly known as P. rosettifolia #3) shown above. There are several variants or clones of this species in cultivation. The one above has attractive leaf markings and large, pure white flowers with yellow throats.

Mr. Shaw finally did some of the much-needed taxonomic work on one of the more popular species in cultivation now for around ten years. In his article, Mr. Shaw mentions the fact that this species has been improperly labeled P. rosettifolia, and has also been distributed under various other names such as 'G25KC00' which I've discussed here in previous posts. In my collection, I've accumulated at least nine plants which I believe are simply different clones, likely from different collections, of this species. DNA analysis which we did with Niagara University, has shown that these various clones are all very closely related genetically, so close, in fact, that we believe they are all the same species. It is common from a species to contain individuals with quite different characteristics.

Pictured above is a plant in my collection which I call P. cryptica '#5 '(formerly labeled P. rosettifolia #5). This form has less distinct yellow veining in the leaves and lavendar flowers.

Pictured above is P. cryptica '#4' (formerly labeled P. rosettifolia '#4'). This form has white flowers and a distinct and vibrant yellow veining to the leaves. The flower form on this clone, to me, is less attractive than that of #3, but it tends to flower more heavily, and later than '#3'.

The photo above shows the variability in the foliage of P. cryptica clones in cultivation. This photo shows my plants of P. cryptica '#4' at the top and P. cryptica '#1' at the bottom. Two forms #1 and #2 both have leaves that are nearly totally green and more rounded in shape with smooth margins. Other clones show the distinct yellow veining and toothed leaf margins. Clones #1 and #2 also grow much more compact and have flowers in light lavendar to pink shades. DNA analysis, though, does show them to be the same species as the showier forms.

Mr. Shaw's article has lots of good information in it. And, it mentions this blog and three of my hybrids using P. cryptica - P. 'Rosemary Platz', P. 'Keystone's Bantam', and P. 'Keystone's Harvest Moon'. The first two are registered with the Gesneriad Society and show P. rosettifolia as the parent, since that was the name applied to the species at the time.

In the future, I hope to see more taxonomic work done on the many Pet species still being grown and distributed under names that are clearly incorrectly applied. P. minor and it's various forms being one in this group. P. sericea and sp.' HT-2' are also suspect in my opinion.

So, the question I am getting is "Should I change the labels on my plants?". I have changed my labels on the plants which I am reasonably certain fall under this newly published description. If I am in doubt, however, I say what I always say...keep the plant labeled as you acquired it, along with a notation of where and when you acquired it. One day, perhaps we will have the mess with Pet names sorted out. For the time being, though, enjoy growing the plants as they are.

A Sincere "Thank You"

2011-11-29T17:10:00.005-05:00

Petrocosmea sericea, in my plant room this morning!

I've missed blogging about my favorite plants। Sometimes, one is blessed with lots of "passions" in life, and priorities must shift. With only twenty-four hours in a day, and only one of me, the time left for plant passions is limited to only enough time for watering and maybe a little fertilizing and repotting. I'm happy to say, though, that at least for the moment, I'm finding a bit more time to not only water and fertilize, but also to stop and smell the Petrocosmeas (see my last post!!).

Most importantly, I must stop to say a most sincere "Thank you" to all of you who have taken the time to write, share photos, seek advice, and tell me of your experiences with Petrocosmea. It means a lot to hear that you have found the posts here on the blog helpful to your enjoyment of Pets. In the time that I have been away from the blog, I have continued, as time permitted, to do some experiments, study both old and new species, and to continue to grow and evaluate new seedlings for future release. I continue to learn so much about these plants every time I work with them. The feeding, watering and fertilizing may have been scarce, but my enthusiasm for the Pets remains. In your letters, you have given me many ideas for future posts, and I will do my best to get to those as soon as I can. Thank you for the suggestions, comments, and questions.

So, this morning, having a rare day off, I arose early and went to the basement to work with the plants. I was welcomed by the plant pictured above...Petrocosmea sericea, giving it's annual show of bloom. The plant pictured is now about ten years old. It was one of my earliest acquisitions as a gift of two leaves from a friend. This senior amoung my collection has been in the same pot for about four years now. It is potted in a 1:1:1 ratio mix of peat, perlite and vermiculite and is in a five inch pan pot. It sits on an acylic matting that is occasionally moistened for humidity. Humidity in my basement never gets below around 50% year round, and is often higher. This summer, as my work schedule has gotten busier, this plant has wilted several times and has only been fertilized maybe twice in the last year. But it is happy. This photo reasserts my advocacy of letting Pets dry out between waterings, and for going light on the fertilizer. One of the most common questions I get is "why won't my Pet bloom?" Often, with some questioning, I hear that the plants are kept constantly moist and fertilized often. It is true that his treatment makes lovely and lush foliage, but I fear it is at the expense of flowers. Pets in nature often grow in rather harsh conditions where they dry out between rains. Prior to taking the photo, I removed 17 spent flowers and there are 68 flowers still on the plant, if I counted them correctly. It makes a lovely sight and you can see the flower potential if given proper culture. SO, this morning, being greeted by this lovely sight, I took the time to stop and smell the Petrocosmeas! (I have three of these P. sericeas in bloom now.) And remember, this species is fragrant.... the scent is great! I hope you have some Pets in bloom to enjoy too~!!

Petrocosmeas with Fragrance

2011-07-24T20:19:00.003-04:00

I've posted about this before, but wanted to remind those of you who are growing P. minor or P. sericea, or P. sp. 'HT-2' to sniff the flowers when they bloom for you. This year, in the GS Convention show, Paul Kroll entered a flowering P. minor. This was an unusual entry since P. minor rarely blooms at this time of year. I used this opportunity one morning in the showroom to conduct an informal survey with those who were viewing the show.

I asked ten people to sniff the flowers of the P. minor. Seven of the ten people could detect the fragrance. It was mid-afternoon, and for me, the flowers are most fragrant very early in the morning, but still the fragrance was there. Of those who could smell the fragrance, I asked them to describe it. All said "spicy", four also detected a floral scent along with the spice.... two said it reminded them of carnations. Three people could not detect the scent at all. I find that for many of the gesneriads that have fragrant flowers, there are always a good percentage of people who cannot detect fragrance. Covering or enclosing the blooming Petrocosmea will also help to concentrate the fragrance. I also feel that some clones are more fragrant than others. The veined leaf form of P. minor, the one often labeled P. sp. #5 is the most fragrant.

So, just a reminder to take the opportunity to enjoy yet one more incredible trait of these fabulous gesneriads!! SO take the time to "stop and smell the ....Pets!"

Petrocosmea minor Kinship group

2011-07-24T19:57:00.004-04:00

This year, I entered my first Petrocosmea Kinship Collection in the Gesneriad Society Convention show. A Kinship group is an effective way to showcase a parent and its offspring. Dominant characteristics can easily be illustrated with this type of entry, as well as utilizing the entry to introduce new hybrids.

I chose to showcase Petrocosmea minor and four of its hybrid offspring since P. minor has been quite the challenge to hybridize with. It has never performed successfully for me as a seed parent, and has only functioned as a pollen parent in three crosses so far. I must have pollinated a hundred flowers, actually likely more than that. Last year, I think I applied pollen to every P. minor flower that opened, all failures. The crosses that have worked have been P. minor crossed onto P. forresttii, P. sericea, and P. rosettifolia. The cross with P. sericea, which like P. minor has fragrant flowers, also produced fragrant offspring.

Pictured above is my Petrocosmea minor Kinship Collection. Starting with P. minor at the top, and moving clockwise, there is P. 'Paul Kroll', an unnamed seedling of P. rosettifolia x minor, P. 'Keystone's Blue Jay', and P. 'Keystone's Slippery Rock'. I used tan fabric as a unifying drape for the collection since I like the brown tones against the green Pets....

Pictured above is a new hybrid P. 'Keystone's Slippery Rock' which is P. forresttii x minor. This cultivar had lots of flowers and inherited a nice compact rosette from P. forresttii and the shiny round leaves of P. minor. It was my favorite seedling from the cross. Slippery Rock is a city about an hours drive north of my home in Pittsburgh, in western Pennsylvania. The glossiness of the leaves reminded me of a slippery quality, so the name was to honor a great university town in PA.

Pictured above is P. 'Paul Kroll' a sibling from the P. forresttii x minor cross that produced P. 'Keystone's Slippery Rock'. This plant has flatter leaves with more prominent veining, a dark green round leaf with a bluish coloration and a nice combination of glossiness and hairness to the leaves. It was the most floriferous plant from the cross, producing LOTS of flowers. You've heard me mention my friend Paul on here before. Paul is a skilled grower of Pets and has shared lots of new Petrocosmeas with me over the years, so I wanted to honor him with this new hybrid.

The Kinship group got lots of positive comments and received a first place ribbon from the judges. I had lots of requests for leaves of the new hybrids, so I hope they will be enjoyed by other admirers of Pets soon.

Petrocosmeas Go To Convention!!!

2011-07-17T12:16:00.003-04:00

Well, the annual international convention of the Gesneriad Society is but a fond memory now, but what a great time we had! Philadelphia was the site for this years convention and the fast-paced week was full of fun, friends, and of course gesneriads! While I do love the plants, I always leave convention reaffirming that the chance to spend a week among friends who also love gesneriads is the best part, and this year was no exception. On the Petrocosmea front, Pets got their fair share of attention. I was overjoyed to see some of my own hybrids being grown and shown by others....a "high" that every hybridizer enjoys.

Petrocosmea 'Keystone's Bantam' won big this year and was selected 'Best Petrocosmea'. The plant was grown and shown by Richard and Nancy Carr of Ohio. An interesting story about this entry was that the classification committee almost didn't let Richard and Nancy show the plant as 'Keystone's Bantam', insisting that it was actually P. rosettifolia. I was asked to come over and help to sort out the confusion, which we did. The Classification Committee were simply unfamiliar with the characteristics of the hybrid, and honestly thought they were helping the exhibitor to correct some mislabeling. The distinction, when out of bloom, is that 'Keystone's Bantam' is significantly smaller in leaf and rosette size and a bit hairier than the species P. rosettifolia. A P. rosettifolia with that much leaf volume to the rosette would have been three times the size of the little plant that the Carr's were attempting to enter. The confusion was quickly cleared and the plant was entered. It did well in the judging too! I was as proud as the Carrs were, I think!

P. 'Keystone's Bantam' also showed up in the Photography classes, and performed well there too! Dale Martens did a very skilled job of photographing her little plant early one morning just as the sun was rising and casting a golden glow upon the little plant. She captured this in the photo and the judges recognized her skill by awarding her a First Place in the class and 'Best Photograph' for the Division. Dale, a dear friend of mine and my hybridizing mentor, kindly gave me the photograph after the show! I was touched by her generosity and the photo now hangs in a prominent place in my living room.

Mary Lou Robbins won a second place award for her needlework interpretation of a photograph from this blog, taken of my hybrid seedling P. forrestii x sericea. Mary Lou wrote some time ago asking for permission to use the photo in a craft entry, and this is the result. I loved it! She even used longer tufts of thread over the calyx lobes to mimic the hairiness of this hybrid. It was a First Place effort in my book Mary Lou!!!

Another friend, Paul Kroll, executed a wonderful design using a Petrocosmea sericea as a focal point in his design. The theme was Punxy Phil, the legendary ground hog from Punxsatauney, PA, who emerges each February 2nd to predict the arrival of spring according to whether or not he sees his shadow. This design required that hairy and fuzzy gesneriads had to be incorporated into the design. I loved this one! The pieces of slate at the base were intended to suggest Phil's shadow.

This photo, taken on the last evening of convention shows some of my dear friends and mentors in my gesneriad adventures. From the top left are Dr. Bill Price, Mary Lou Robbins, Ben Paternoster, myself. Middle row L to R are: Paul Kroll and Arleen Dewell. Front row L to R are: the legendary and beautiful Rosemary Platz, namesake of my first Petrocosmea hybrid, Karyn Cichocki, Dale Martens, and Jill Fischer. We enjoyed a wonderful dinner on our last evening together. Each of these people has taught me something about gesneriads over the years that I have known them. In all things in life, having mentors and friends is most important to success. I have been most fortunate to have lots of both. I wish the same for each of you.........

New Pets From the Netherlands - Foederer Hybrids

2011-06-04T18:41:00.007-04:00

I just love this photo.... it is a photo shared with me by Jeff Foederer of P. sericea growing and blooming outdoors in Jeff's garden in the Netherlands. I've had the pleasure of corresponding with Jeff a few times and am currently growing one of his beautiful xBrigandra hybrids 'Ivory Falcon'. Jeff also produces some spectacular Petrocosmea hybrids, which I thought I'd tell you about.

Jeff was the first person to register Petrocosmea hybrids with the Gesneriad Society when he registered P. 'Lexi' back in 2006, followed by P. 'Milan' in 2007. Recently I received a photo in an email from Dale Martens, asking me to take a look at Jeff's most recent hybrid P. 'Helena' (pictured below). Just take a look at the flower count on that one!!!!! Magnificent!!

Jeff's hybrid, P. 'Helena' is a cross between P. menglienensis and P. nervosa. I can see the nervosa parent in the foliage and the menglienensis parent in the flowers. What a beautiful plant. 'Helena' was registered in 2010.

P. 'Milan' (begoniifolia x nervosa) is another beautiful plant. The flowers seem to dance like butterflies above the foliage. P. 'Milan' was named for Jeff's grandson, I believe.

Jeff's hybrid P. 'Lexi' (barbata x flaccida) is a small grower, looking much like P. barbata in habit, but then the lovely blue flowers emerge and it is clearly not P. barbata. I'm happy to say that I've grown this one for a couple of years now and really enjoy it. It too was named for one of Jeff's grandsons. This represented the first use of P. barbata in hybridizing.

Ornamental Value - Judging Petrocosmea Out of Bloom

2011-06-04T06:34:00.004-04:00

WARNING: I'm going to offer an opinion in this post that you may find objectionable.... reader discretion is advised.

Please take a look at the photo below and notice two things.... First, notice the number of entries. This is the "Grown for Foliage" class for Petrocosmea at the 2009 Gesneriad Society Annual Convention Show in Silver Springs, MD. The intent of this class is to provide a place to enter those nonflowering gesneriads that possess significant ornamental value for the parts of the plant other than the flowers, such as foliage, stems, calyces, etc. There were around 30 entries in this class. It was subdivided into about five or six smaller classes due to the large number of entries. Secondly, and perhaps more importantly, take an objective look at the entries on the table and ask yourself if there is anything particularly ornamental about them. Granted you cannot see them well due to the distance of the photograph from the individual entries, but is that anything about them that makes you say "wow" what a striking plant?

As a keen admirer of Petrocosmea, when I first viewed this section of the show, I said, "wow" but that was due to the number of entries. However, once I got past that, as I looked at them, I had to ask, "why are all of these entered into the foliage class of the show?" Now, remember, those plants entered out-of-bloom for judging are intended to possess some particularly ornamental quality about the foliage or the plant habit that is ornamental. At this point in the argument, people usually challenge me by saying that "Petrocosmea has an ornamental growth habit to the foliage". Granted, many of the Pet species do have a pleasing foliage habit. That flat, symmetrical, spiraled pattern to the foliage rosette is attractive, and has some ornamental value. Notice I said "some". But, many Pet species do not have this...kerrii, barbata, nervosa, often flaccida and parryorum are not particularly pleasing as they want to grow. But, others like forrestii and minor just "do that"...they generally, without any intervention from the grow, just naturally form and near-perfect rosette. But what else is there to make them ornamental...and by this I mean ornamental ENOUGH to rise to the level of a first class show specimen? I say, not much else is there in most cases. The fact is, in my opinion, in most cases the average Pet, when out of bloom is just a plain green plant. Consider other plants that do this...Sempervivum, Aeonium, Haworthia, many Primula, Bromeliads, and even many Saintpaulia hybrids do this....but do we see them on show tables entered when they are out of bloom? Usually, No if the leaves are plain green with no other coloring, variegation, etc. Why don't we see these other plants entered when out of bloom? Because they are not showy enough to win awards if they are not in flower.
Consider this blue ribbon and Best In Class winner above...P. forresttii. Other than the form of the rosette, is there anything particularly ornamental about this plant? It won these high awards based on the ornamental value of the foliage in large part..... Should it have? Do any of us believe that the grower here likely had to exert any great effort to get the plant to achieve this shape and symmetry? Probably not....P. forrestii just grows that way without any intervention.
Another first place winner above...P. barbata. Anything striking about the foliage on this one? It is a lovely little P. barbata...... but is it ornamental enough to get such a high score?

So then, why are these plants getting such high awards and why are we seeing so many of them entered for Ornamental value in shows? My thoughts are that we are still getting over the "new and rare" effect that we so often feel and see when new species and hybrids are introduced. Most Pet species in cultivation in the USA and Canada right now have only arrived within the last decade or so. Prior to that we grew P. parryorum, P. flaccida, P. nervosa and P. kerrii. P. formosa came along around 1998. Then in the years following that we had P. forrestii, P. minor, sericea, rosettifolia, etc, etc. So for many growers we're still infatuated with the "new-ness" of these plants. Yes, they are charming, and interesting ,and new, and rare, but are they strongly "ornamental" when not in bloom and when you exclude those factors? No... in most cases it's a plain green leaf...sometimes with a bit of silvery hairiness, or a curled leaf margin, or a bit of yellow central veining as in some of the rosettifolia clones, but do they rise to the level of Episcia 'Cleopatra' or Pearcea hypocyrtiflora, Gasteranthus atratus, or Smithiantha cinnabarina? THOSE are the plants the ornamental foliage classes were intended to accommodate in shows... plants that you can spot from across the room due to the striking foliage.

Lets consider, though, that I am being a bit harsh, and lets accept the argument that it is the foliar rosette, and that flat, perfectly symmetrical form and habit to the growth pattern that IS the ornamental quality which makes a Petrocosmea ornamental when out of bloom. Okay, lets explore that. Granted, the public often approaches a Petrocosmea in a showroom and says "WOW, look at that!... Look at how perfect it is!" I've spent a great deal of time standing near the Petrocosmea section in a showroom with the sole purpose of observing and studying the public's reaction to my favorite genus. I've seen and heard this reaction many times. So, in fairness, yes, there is something quite ornamental about the form or habit of the plant itself. If we are then to accept and make room for this , then certainly one should expect near perfection in this regard for the blue ribbon Pet entries. But we're not seeing that. Think back to the last few shows you've attended or photos you've seen of award winning Pets that were out of bloom.... were those plants on the table the best of the best with regard to form, symmetry, even pleasing shape and habit? Were they mature plants in all cases? To rise to the level of a show specimen, they should exhibit evidence of maturity, careful and consistent care, shaping, training and grooming. Given the ease with which most Pets naturally shape-up as they mature, judges should be requiring a first place winner to be perfection in most every regard. The form of the rosette should be a perfect circle without gaps in the leaf pattern.

Take a look at this first place winner above... P. menglienensis. It appears to be little more than a starter plant, with a rosette that is weak and open, and asymmetrical. There are gaps and it certainly is not a perfect circle. Leaves are really pretty much plain green leaves. Why a blue ribbon? Giving such a plant a blue ribbon does not do the exhibitor or the public any favors. There is often the argument to "be kind" in judging and just reward the effort to bring it in for the show. Huh? Awarding such entries high awards misrepresents that standard and potential for the plant, as well as misrepresenting the basis of the whole judging process. That does no one a favor. Better to take such an opportunity to educate the exhibitor and the public. That is the duty of the judges in such a situation...education. This is a healthy, young plant, with great potential to become a large, attractive flowering plant which will demonstrate the true potential of this beautiful species. But, P. menglienensis is a plant that most likely will always perform best as a show specimen when in bloom..... it possesses nothing particularly ornamental when out of bloom, whether large or small.

So, there it is. The opinion of someone who has spent a lot of time over the past few years learning about, and growing to love the genus Petrocosmea. I grow them, I bloom them, I hybridize them, and yes, I even fail with them. I also judge them as a master judge for the Gesneriad Society and I DO exhibit them.... Almost without exception, I enter them as either a "New Species" when that is the case, or as "New Hybrids". Perhaps I'll enter them as a collection to show the variation within the genus. They certainly are excellent plants for educational exhibits because we are learning so much about them everyday.. BUT, I am very hesitant to enter them when out of bloom for ornamental value. I simply feel as a judge, exhibitor, hybridizer, and most importantly, as their greatest admirer, even at their best, they lack significant ornamental value if they are not blooming. My purpose in this post is to begin to spark thought and consideration on the part of exhibitors and judges about the current manner with which we treat these entries in shows. I feel that the standard for awarding non-flowering Petrocosmea entries should be re-evaluated. It is kinder and fairer of the judges to educate than to give awards that lack substance. Now, I'm going to go and water my Petrocosmeas......

Stolons, Zippers and Buttons

2011-06-01T19:35:00.005-04:00

Most of what we know about cultivating Petrocosmea is still pretty new information. Many, or rather most, of the species we are growing now only arrived on our plant stands and show tables within the last decade. As we are growing them more, and our time spent with these plants is increasing, we're seeing for the first time in many cases, just what sort of peculiarities these wonderful Pets are capable of. Zippers, buttons and stolons are just three of the manifestations my Pets have produced in the last few years. Since these may be new to growers, exhibitors and judges of Petrocosmea, I thought I would discuss them in a short post.

Buttons ~~~

The photo above is Dale Martens' photo of a "button" that appeared on her plant of my hybrid 'Keystone's Bantam'. There was a recently lengthy discussion on this phenomenon on Gesneriphiles, when a plant exhibited with such a button was marked down in judging . The judges, who were all expert and seasoned judged, had not encountered this anomaly before. One of them contacted me to ask if Pets "normally" did this. I've seen several plants of P. rosettifolia do this during the winter when I was resting them by keeping them drier than usual and cool. 'Keystone's Bantam' does this often, and since it is hybrid of P. rosettifolia, I suspect it inherited this trait from it's rosettifolia parent. I have also seen this once on P. forresttii.

In all cases, the plant produced a new whorl of leaves from the center of the "button" and the plant regained full and attractive symmetry within the rosette with the next cycle of growth.

Above is my photo of 'Keystone's Bantam' at it's first flowering. You can see the center button in the photo. The button appears to be a dense tuft of golden yellow hairs and does not represent poor culture or a rotted or diseased center. It appears to be a normal, although not that common feature of these plants. It is my opinion as a grower and judge that it should not be faulted or penalized in judging unless in the opinion of the judges, it detracts from the overall ornamental value of the plant. But, that's just my opinion...and opinions are like noses....everybody has one.

Zippers ~~~

The next phenomenon in Petrocosmea growth patterns is what I call zippering or zippers. A healthy plant, usually with a few years of age, suddenly starts to produce a center growth point within the crown of the rosette, that begins elongate into a linear growth point. The normally circular rosette can often become more oval in shape, and if grown on, the plant often splits into two or three crowns. Eventually these will totally split or separate producing two or three new crowns. I see this occur often in P. forrestii, and it's hybrids, as well as the rosettifolias and their hybrids. I have seen it occur once in P. minor also. In all cases the plants were three years old or more when this happened. See the photo below of P. forresttii at five years of age, with a zippered crown, which eventually became three separate crowns. The plant flowered very heavily during this period. It appears to me to be more a factor of age that a cultural flaw.

P. forrestii with a zippered crown.

Look closely at the plant in the center of the row on the left above....the one with the yellow ribbon. This photo shows a group of P. 'Short'nin' Bread' entries at a convention show a couple of years ago. The third place winner was a plant with a zippered crown..... it beat out some other specimens with more typical round crowns. This judges, in this case, did not penalize this plant for the zippered crown..... which again, they should not do unless it detracts from the ornamental value of the entry. Good judging in this case...as it demonstrates a panel of judges who were familiar with the habits of these plants. (P. 'Short'nin' Bread' is a P. forrestii hybrid...so it likely got this trait from its forrestii parentage.)

Stolons ~~~

Stolons are yet another trait of healthy Petrocosmeas which we are seeing from time to time. I've seen it on several species and hybrids....so it appears to be possible on just about any Petrocosmea. I have not identified what might be triggering it other than the plant deciding that it wants to make some stolons.... I find it a "cute" phenomenon on most Pets.

Congratulations to B. J. Ohme of Perfect Petals for his first place winning entry of P. 'Short'nin' Bread' at the recent AVSA convention in Cherry Hill, NJ. Wisely, the judges recognized the additional ornamental interest that the stolons provided to this entry and gave B.J. his blue ribbon. P. 'Short'nin' Bread' is a plant that, in my opinion, is most ornamental when shown in bloom. But traits such as stolons can add ornamental interest. (Photo courtesy of Dale Martens..... "thanks, Dale!!!!!" )

So, there they are, the quirks that our Pets are capable of conjuring up to keep us fascinated and infatuated with them. These may be just the beginning of the wonders we will unlock as we enter into a new era of hybridizing with this genus.

Lost and Found - A Tiny Surprise

2011-05-30T18:50:00.003-04:00

One of the first lessons I learned as a budding gesneriad grower was that the first thing one should do when acquiring a prize new gesneriad is SHARE IT! At the very least, propagate it and then share it. Why? Often, events in our lives can get in the way of the care of our gesneriads, or they simply may not like the care we have to offer them, and they die. But, fear not, if we've followed the first rule of growing gesneriads, and we've shared our prize plant, we often can get it back from the friend with whom we've shared it. That has happened to me more times than I care to remember, and recently I was reminded of how true that rule can be.

The story begins a couple of years ago when I wanted to test whether the "miniature" gene that has shown up in my hybrid 'Keystone's Bantam' would be passed along to its offspring. So, I crossed P. forresttii with pollen from 'Keystone's Bantam'. I used forresttii because it was the smallest of all the species I had grown at that time. A seedpod did indeed result, and sure enough, as those zillions of tiny seedlings began to mature, it was evident that something unusual was going on. They were all not only mini's but microminiatures.... the leaves remained the size of a sesame seed on all of them! I thought that was "too miniature" and that they were stunted. So, I repotted them... and began to fertilize them. They were all healthy, but just very tiny. After about a year and a half, I decided they were rejects and tossed them all out. But, I gave a couple of them to a friend who is known for growing spectacular, prize winning Petrocosmeas. I had forgotten all about them until recently when I was visiting that friend. We were making a Sunday morning sweep of the plant room when I happened to notice among the Pets, a tiny little plant. I picked it up and saw the label.... There it was, my tiny little Petrocosmea hybrid...still tiny! See the picture below, with the little plant beside a quarter for comparison. ...........

The plant was growing in a one inch pot, but appeared healthy and thriving....and under two inches in diameter. It is now almost three years old and it remains very small, with lots of tiny leaves in a neat little rosette. So far, it has never bloomed.

My tiny little hybrid Petrocosmea, sitting beside a standard P. sericea. Each of those little squares on the grid is 1 cm x 1 cm. This little guy proves the value of sharing plants AND the value of not being too hasty to make judgements about new hybrids that show new and unusual traits.

The genetics that are showing up within the genus Petrocosmea, as I am getting to grow out more and more crosses are amazing me! Who'd have ever guessed that mini Pets would have shown up so early in this adventure? The variation in flower coloration and extra petal lobes, ruffles, etc is also a wonder to see. I counted around fifty seedlings this morning in the Pet Cave that are yet to flower for the first time...and these from five different new crosses. My excitement with these seedlings in continually renewed.

A happy ending.........I'm delighted to say that my friend shared a dozen or so little leaves from the plant, and they are already forming tiny little babies in my prop box. Now, if I can just grow them on ....and see if they remain minis. I also still have a good supply of the seeds from that original cross in the freezer, so I'll be planting them again this winter. Lesson learned....again?!

Hybridizing - The Ultimate Thrill

2011-05-25T06:51:00.002-04:00

For me, the ultimate thrill of hybridizing has been seeing my own creations exhibited by other growers in a show. At the recent AVSA Convention show in Cherry Hill, NJ, my friend, mentor and exceptional gesneriad grower, Paul Kroll, entered my hybrid 'Keystone's Magic' and won a blue ribbon in the flowering Petrocosmea class. Paul does such a great job with Pets, and this plant was beautiful. Soon after I arrived, Paul came over to tell me that he'd entered a couple of my Pet hybrids in the show. We were both happy with the result.

P. 'Keystone's Magic' is from a cross between rosettifolia #3 and sericea. The cool thing about this plant is that it is showing multiple flowers on each cyme. Both parents, for me, have always had a single flower, rarely two, per cyme. That's a fun aspect of hybridizing with Pets.... I never know what's going to develop. A couple of the cymes on Paul's plant have six flowers per cyme...which shows great potential at increasing the flower count on hybrids. The flowers were larger than in either parent and with several per cyme, I thought the cymes did a nice job of holding the flowers upright.

The flower color on 'Keystone's Magic' is a lovely silvery lavendar, with three yellow stripes in the throat of the corolla. The flowers contrasted nicely with the dark foliage.. My only disappointment was, and always is, the suckering. Many Pet species form suckers at the same time they are forming flower buds...so just as you are about to have a flowering plant, the symmetry of the rosette is all distorted.... but, other qualities of the plant made me overlook the suckers this time. Rosettifolia suckers a lot, so I always expect that in the hybrids...although with hybridizing, suckering does seem to be diminished in the hybrids, compared to what the species does.

Thanks also to Dale Martens, for taking the lovely photos and for sharing them. I was not expecting to get to see the show, as work was causing me to leave soon after my talk. ...but I did get to see the show, as a surprise. So lesson learned.... Don't ever go anywhere near a show without my camera!!!

I'm Still Here!

2011-05-23T17:40:00.002-04:00

Yes, it has been a while since I posted to the blog. My apologies to those of you who have waited so patiently and supportively for more news from the world of Pets. I appreciate so much the emails inquiring about me and the blog. A busy work schedule and travel schedule have kept me away from posting, but NOT away from the Pets. It is good to be back, and I have outlines for many new posts and topics to come.

So here's whats happening with our beloved Petrocosmeas.....

First, I named the basement growing room where I cultivate the majority of the Pets. I get lots of inquiries about my growing conditions. I grow my Pets in a basement room that once functioned as a large coal bin back in the early 1900's when my home was built. Pittsburghers used a lot of coal, I guess, and basements often had a room partitioned off from the rest of the basement for the purpose of storing the coal. Mine is a block room with one tiny window. I've begun calling it the "Pet Cave".... so you'll see me refer to the Pet Cave from time to time. And the Pet Cave has been busy over these last few months that I've been away from the blog. It has even churned out a few show winners this spring!

Petrocosmea 'Keystone's Angora' scored 94 points and a second place ribbon at a recent show where I both judged and exhibited a few of my new plants. Since the judging is competitive, compared to AVSA judging which is merit judging, the plant got a second place ribbon in the New Hybrids Class. I'm always happy when one of my new hybrids scores well. I was proud of this one. Judges loved the velvety foliage, and I allowed them to "pet it" after judging. (By the way, I did not judge this section! )

Another of my new Pets, this time a newly cultivated unidentified species from China. It scored 93 points in the New Gesneriads class and got a first place ribbon. I'll post more on this species, plus a couple of others in a future post. This plant was exhibited quite small, but seems to be a compact grower.

Petrocosmea 'Keystone's Little Rascal' (above) is a sibling to P. 'Keystone's Angora' in the first photo. It was also entered into the New Hybrids class and got the first place award, with a score of 96. This cultivar stays very small, under four inches on the average, with smaller leaves and flowers than it's siblings. The flowers most often have six or more petal lobes and the plant after two flowerings, has been very floriferous. I included a photo of the plant in bloom for the judges to see what the flowers look like, since the show was in the spring, and that is outside the normal bloom season for most of my Pets. After the show, I shared lots of leaves with judges and growers, so I hope to see these in wider cultivation soon.

So, in addition to growing and hybridizing, I've judged a spring show, given three talks on Pets to various AV and gesneriad chapters including a talk last week at the AVSA convention in Cherry Hill, NJ, and have recently co-written an article on Judging Petrocosmea Out of Bloom for Appraisal, the journal for judges for the Gesneriad Society. It's been a busy winter and spring, but I am very excited to be blogging again!

Hybridizing Petrocosmea - A Family Portrait

2010-12-06T21:18:00.003-05:00

A Family Portraint showing P. rosettifolia #3 in the back, the seedpod parent of my first two hybrids...P. 'Keystone's Bantam, in the front, left and P. 'Rosemary Platz' on the front right.

With Petrocosmea season in full swing here in southwestern Pennsylvania, I'm enjoying an abundance of bloom. Yesterday I counted 58 Petrocosmeas in bloom, with almost as many still forming buds and yet to flower. But, no matter how many Pets I have in bloom, or how many are yet to come into my collection, two will always remain special in my heart...my first two hybrids. Petrocosmea 'Rosemary Platz' and P. 'Keystone's Bantam' are now currently in flower along with one of the parents P. rosettifolia #3. I had to take this occasion to take a photo of the three together for comparison.

P. 'Keystone's Bantam' with it's white flowers, each larger than it's leaves, and P. 'Rosemary Platz', which seemed to inherit all of the best features of both parents of the cross. I still have such a clear memory of the morning in October, 2007 when I made the cross, by applying pollen from P. sericea to the flowers of my favorite form of P. rosettifolia...the form I labeled #3. Within a couple of weeks, the seedpods were forming, and I remember thinking that they would probably contain no seeds, or if they did have seeds, they would not germinate. But, those three pods DID contain viable seeds and they were planted the following January, 2008. First flowers appeared in October and November of that same year. Through the whole process, I remained in disbelief that I had been able to finally produce seedlings after ten years of failed attempts.

Little 'Keystone's Bantam' was the oddity of the cross. It remained tiny from the very beginning. While it's siblings all grew quickly, it reached about 1.5 cm and stopped getting larger for months. Finally, that tiny green button of foliage did slowly get larger until it was 2 inches in diameter, when buds began to form. That original plant, shown above, remains under three inches today...more than three years later. This is it's third year of bloom. The tiny leaves are deep green, almost black at times, with the lighter yellow central veining of its P. rosettifolia parent. This was also the only white flowered seedling in the batch of more than thirty that I have flowered to date. The only 'tiny' one. I chose the name in honor of my dear friend and fellow Petrocosmea enthusiast, Paul Kroll. In addition to growing spectacular Petrocosmeas, as well as most other gesneriads, Paul grows, shows, and judges Japanese bantam chickens. The fantailed appearance of the flowers on 'Keystone's Bantam' reminded me of Paul's little chickens. Paul grows tiny little chickens, but his Petrocosmeas are gigantic.... I often say the Paul Kroll can grow a 12 inch Petrocosmea in a bottle cap! He phoned me this evening to tell me that his own plant of 'Keystone's Bantam' is now in bud also!!

The star of my first hybrid cross is indeed P. 'Rosemary Platz'...my very first named hybrid Petrocosmea. I named this hybrid in honor of another cherished friend - Rosemary Platz from Long Island, NY. Everytime I see this plant flower, I am reminded of how lovely my friend is. The flowers on this hybrid have a pleasant yellow throat with white and silver lavendar lobes on the corola. Flowers most resemble the P. sericea parent. Leaves are glossy, intermediate in shape and size between both parents, and with good culture, often show a subtle lighter veining. I have been very proud to see this hybrid showing up an winning some blue ribbons in shows when exhibited by other growers.

The Difference a Year Makes.... Petrocosmea cavaleriei

2010-12-06T20:27:00.003-05:00

One of the interesting points I'm learning from the study of a single genus, day to day, for several years now is that Petrocosmea plants clearly evolve and change over time. One theory I'm starting to consider is that Petrocosmea may indeed progress through different "phases" or stages in development over time, as the plants mature. I've seen this with most of the species now. As young plants the leaves, flowers, pedicels or cymes, ...almost every characteristic of the plants, seem to change over time. Recently, I've been studying this, and have found a number of articles that discuss the molecular changes that the leaves of various plants go through as they mature.... I've begun to wonder whether this is truly what I am seeing with Petrocosmea, or if they are simply "growing up" and it takes more than a couple of years for them to mature.
I guess that is a topic for another post at another time...but the second annual flowering of a relatively new species to my Petrocosmea collection just makes me ponder my theory even more.

You may recall a post from October of last year, where I first introduced you to this species. While flowering is a bit later this year, the plant is putting on a spectacular, and more impressive show than it did last year. I also mentioned last year that I had begun sharing leaves of this species with a few friends. It has been fun, and rewarding, to get email and calls from those friends over the last few weeks, as the plants they propagated from those leaves are also flowering for them.

The photo above shows the same plant as the one in the photo below....it's just a year older now... Do you see a difference? Dramatic isn't it? The rosette really isn't much bigger with regard to diameter...but it does have more leaves. The plant remains in the same pot as it was a year ago when it first flowered. The plant now has a diameter of exactly four inches. Flowers are larger, and are dancing on the ends of purple pedicels. For such a small plant, it is making a dramatic show, and I am thrilled to have it in my collection. I've maintained three plants, and all three are nearly identical.

Just to refresh, my label reads : P. cavaleriei 'ABG 2005-2221' TT04. This label tells me that the plant came from the Atlanta Botanic Gardens, was collected in it's natural habitat in 2005. The 2221 is the ABG's accession number, and the TT04 is my own accession number, which ties to the records I keep of all of my Petrocosmea species. I make sure to pass these numbers along to anyone who I share leaves with. The species was collected in southwestern China.

The same plant flowering in the first photo, as it looked a year ago upon it's first bloom. Don't measure your Petrocosmeas by how they perform the first year or two after you get them...they must mature to show true potential. I am still amazed at some of my plants as they grow into the sixth, seventh, even the tenth year in my collection.. They impress me more each year.

An individual flower of P. cavaleriei shows that it fits easily into Petrocosmea Section Anisochilus. DNA studies show that it is very closely related to P. sericea and P. sp. 'HT-2'. I also detect a faint fragrance from the flowers of my plant, although not as much as I can smell from sericea or 'HT-2'. While sericea does not produce branched cymes for me, cavaleriei and sp. 'HT-2' do produce branched cymes with maturity. Like it's close relatives, this species likes to be grown a bit drier with regard to watering and drainage of the soil. It also seems to look best with a bit more light. Leaves, if kept too humid and splashed with water, will form the bleached spots often seen on African violets. P. sericea and sp. 'HT-2' also show leaf spotting, while I don't see this phenomenon on other Petrocosmea species.

An additional note regarding propagation... this species, as do other Pets with heavily felted leaves, will rot easily if the rooting medium is kept too wet during rooting. I avoid this by not burying the petioles, but simply laying them gently on top of the rooting medium such that the tip of the petioles just barely touch the medium. I've often had these species form plantlets when the leaves broke off and fell onto the acrylic matting I line my trays with.

I hope that with time, this species will get wider distribution among Petrocosmea enthusiasts, and that we will see it more often in plant shows. Since it does not have particularly ornamental foliage, however, it would likely do best in a show as a flowering specimen. Still, it is a fascinating new species to have in one's collection.

Fertile Forresttii Does It Again!

2010-11-16T18:10:00.000-05:00

Little Petrocosmea forrestii is a mother again! While there are still some species that refuse to hybridize at all for me....like P. parryorum, and P. kerrii, and P. sp. 'China 2005', the species P. forrestii is taking up the slack for those species. So far, P. forrestii hybridizes more than any other species...having served as a mother in at least a half-dozen crosses for me. This year, I'm watching buds on P. forrestii crosses with sericea and minor.

The first of the forrestii x sericea seedlings flowered this week. I only got five seedlings from the cross. All five seedlings are showing buds. Foliage shows variation with some leaves narrow and cupped, like sericea and others showing rounded, flat leaves more like forrestii. All are quite small so far. I have them growing in two inch condiment cups, that have a capacity of two ounces...(I think.) Most are about the diameter of the cups...around two inches, with the largest, the first to flower...being about 2.5 inches in diameter. This seedling basically looks like a tiny P. sericea, with rounder leaves and very little of the cupping seen on sericea.

See the first flower to open below:

The first flower on P. forrestii x sericea..... can you see both parents in the flower? The flower is about the size of P. sericea, with a bit more of an upper lip to the corolla. A prominent white spot on the three lower lobes clearly comes from P. forrestii...although, sadly, none of forrestii's yellow came through. The dark purple blotch seen deep within the throat of P. sericea did come through in the progeny, and is just visible in this photo. Lower lobes are a bit more narrow and longer....more like forrestii.

The first seedling to flower from the cross looks much like a tiny P. sericea, although leaves are not as cupped as sericea.

This photo was a challenge....and my lack of photography skill didn't help anything. But, here is my best effort to show "MOM"...P. forrestii (left), "DAD", P. sericea, (right) and the seedling in the center. A side by side comparison shows the characteristics of both parents in the first flower.

I wonder, and wait, for the flowers on the other four seedlings. (P. forrestii x minor is just now showing buds peeking above the foliage.)

Petrocosmea 'Keystone's Bluejay'

2010-11-12T12:12:00.003-05:00

"Just living is not enough - one must have sunshine, freedom, and a little flower". Hans Christian Andersen

I'm enjoying a beautiful day at home, with brilliant sunshine outside, and the beginning of Petrocosmea's peak bloom season inside. My spirits really got a boost this morning when I went down to my basement growing area to find the second flowering of one of my hybrids in full glory underneath the lights. The hybrid was one of the most challenging to produce. The only seedling that I kept from around tewnty that I grew from a cross between P. sericea and P. minor veined leaf form. I have named this hybrid Petrocosmea 'Keystone's Bluejay'.

P. 'Keystone's Bluejay' is one of my largest hybrids, and certainly one of the most challenging to create. P. minor had been particularly reluctant to hybridize. This cross was my first success with that species as a parent. The large blue flowers show an attractive ruffled texture, are significantly larger than either parent's flowers, and are distinctly fragrant. The scent is a spicy rose fragrance to my nose.

The plant is large, with rounded glossy leaves overlaid with a frosty silvery hair from P. sericea. The plant looks like a very large, frosted version of P. minor veined leaf form. The plant in all of its characteristics, is larger than either parent. The plant shown above is two and one half years old, growing in a five inch pan pot, with outer leaves 2.75" in diameter. The flower count is a nice surprise, since both parents can be shy bloomers with regard to flower count. The outer leaves are showing the yellowing of both age and neglect, which the plant suffered during this past summer. It tolerated the neglect well. Once flowering is complete, the plant will get some fresh soil and a little more tender loving care as a reward. Some dimensions on this plant are as follows: Total diameter of rosette is 11.75" (30 cm). Largest leaf diameter is 2.75 " (7 cm) and flower width is 1.25" (3 cm).

A close-up of a flower shows the ruffled texture of the flowers. The coloring in the photo is accurate and was taken in natural light.

This photo, from a previous blog post, shows P. 'Keystone's Bluejay' as a younger plant, when it won Second Best in Show and first place in New Hybrids' at the African Violet and Gesneriad Society of Western New York show last March in Buffalo, NY. I have been really happy with the performance of this hybrid. The extra effort was worth it!

Here they come!!!! The Year's Crop of New Hybrids Begin to Bud

2010-11-01T19:51:00.001-04:00

"Take thy spade...it is thy pencil. Take thy seeds, thy plants...they are thy colors." William Mason

When it comes to artistic talents, as the quote above implies, I definitely have to rely on my little collection of plants to showcase my "creative" talents.... Assuming of course, that I have any talents. But, for reasons not fully understood, Petrocosmeas have finally decided to hybridize for me. After ten years of attempts and struggling to get even a single seedpod, or a single seed for that matter, the last few years have allowed me a bit of luck.

Last year, I harvested seeds from 14 different hybrid crosses. Of course, I don't have the space to grow them all, but I did plant a few, and the rest are stored in the freezer for another season. The cross which I am most excited about is shown below...P. forresttii x P. minor smooth leaf form.

The largest, and first, of eleven plants from the cross to make buds! P. forresttii x P. minor smooth leaf form was a cross that I made with the goal of getting the round, glossy leaves of P. minor on a small, neat plant like forresttii. So far, the plants look a lot like P. forresttii, but the leaves are rounder, and that lovely glossiness of P. minor is certainly showing up in varying degrees among the seedlings. A couple show very little of it...and look much more like P. forresttii...but the majority do show the clear influence of P. minor in the leaves. Some are staying quite small, others growing larger. The largest, pictured above, is now 4.25 inches in diameter.

While the seedlings are showing great promise of meeting my goals for the foliar characteristics hoped for in this cross, the final test with this, as with ALL of the P. forrestii crosses so far is.... "will the inflorescences, or pedicels, be short and strong, like P. minor (lets hope!!!) or will they be long, wiry and untidy...as with P. forrestii ( boo, hiss, hiss...) . P. forrestii, unfortunately, has proven to be dominant with regard to the thin, wiry, messy, tangled pedicels. While I do like the individual flower characteristics of P. forrestii's flowers, I am clearly NOT a fan of the habit of those pedicels it produces. One last concern for this cross will be the flower count. P. forrestii can be quite easily flowered, and quite floriferous, while P. minor often can be a bit shy to produce a heavy bloom count. Thankfully, both of these species very rarely produce suckers, so that standard goal of my hybridizing program will hopefully not be an issue with these youngsters. Still, one of the joys of hybridizing for me has been....that....one never knows what the combination of genes from two gesneriads will produce.

I'll keep you posted!

Petrocosmea parryorum....an update....

2010-11-01T19:15:00.003-04:00

"A garden is never so good as it will be next year." Thomas Jefferson

The quote above, by one of my favorite American Founding Fathers, reminds me of my experience in studying the genus Petrocosmea for the past few years now. And, P. parryorum is a prime example.

I posted a couple of months ago, how my original specimen of P. parryorum, which has spent a decade with me now, is still teaching me lessons and revealing its secrets with each new season. This year, it bloomed twice...once in January and again, starting what has been a very long and productive season of bloom in August. It continues to flower its last few remaining buds, three months later. That means that to date, this glorious species has been in flower for me nearly one half of the year! And, it is still going!

Pictured above, the now quite ragged and tired plant is still supporting the last few buds, remaining on the final 11 inflorescences. Here's the progress report so far.... it began with a rosette of leaves that was well over 14 inches in diameter when the first buds opened. Now, it has dropped the outer ring of leaves...likely due to the redirecting of energy into the flowers. It has produced 14 inflorescences, with as many as 57 buds on each inflorescence!!! Yes, that's correct...I removed one, pictured below, so that I could count the buds and also to preserve it in my private little "Petrocosmea herbarium" where I press and dry the various structures of each species Petrocosmea in my collection. SO, at around 50 buds each...I estimate that this plant has now produced around 500 flowers in one flowering season!!!! I've been amazed at this plant!

A dried Petrocosmea parryorum inflorescence. Some of the buds in this photo are underneath other buds, and a couple accidentally broke off, as can be seen on the left of the photo...but this one, and one other that I removed, each sported over 50 buds...the one above had 57, the other 54. I would surely love to get this influence incorporated into some Petrocosmea hybrids, but alas, I have not yet found a single flower on the plant that had pollen!! Attemps to pollinate it's flowers with other Petrocosmeas has resulted in no success. I have to wonder if the fact that it flowered during the late summer, when we were quite warm, might have affected the pollen production. I've consistently had better pollen production and better success with hybridizing in the middle of winter when temperatures were quite cold.... The flowering of this plant last January did produce pollen in the flowers.

A close up of a few of the current inflorescences on the plant above...showing a mix of spent flowers, open flowers, and a last few remaining buds.

I wonder what next year will reveal about P. parryorum...the Petrocosmea from India.

Autumn, and Petrocosmea season begins!

2010-10-31T18:22:00.002-04:00

"My green thumb came only as a result of the mistakes I made while learning to see things from the plants' point of view" H. Fred Ale

Petrocosmea flaccida 'ABG 1998-5551' a new clone of this old, dependable species.

Petrocosmea season always really gears up into full swing for me in the autumn. Those cool, damp nights make the cool-loving Petrocosmeas very happy. It always amazes me that even though they are growing indoors, under lights on timers, and all of this is done independent of the weather outdoors, the plants always "know"...they know what the climate outdoors is doing.

This year, I'm especially enjoying a darling little plant that I acquired about three years ago as a gift from a friend at the Atlanta Botanic Garden in Atlanta, Georgia.... A new collection of Petrocosmea flaccida. This clone was collected in 1998. I was delighted to get some "new blood" in the form of a new collection of Petrocosmea flaccida. I am growing, and have distributed this plant under the clonal designation 'ABG 1998-5551', which is the ABG's accession number.

I first wrote about this clone on this blog last year, when it flowered for me for the first time. Now, with another year of maturity, I've had the chance to watch how it performs when grown under identical conditions to my original P. flaccida, which I've had for years. I find this clone superior for a couple of reasons. First, it does not sucker nearly as much as the original clone. Those of you who follow my blog know how I dislike this pesky trait of some Pet species...so finding a clone which has less of a tendency to sucker is a positive characteristic in my opinion. Secondly, it shapes nicely and remains quite small....about half the size of it's larger sister, my original clone of P. flaccida. Leaves are quite small...more like the size of P. forrestii leaves. I would love to hybidize with this clone to see if it contributes to smaller Pet hybrids. I've tried several times to cross it with the original P. flaccida and to self it...without success. I think this may be due to the fact that both forms bloom early in the season...when it is still pretty warm...and I have much greater success with setting seedpods with the temperatures are much colder.

An overhead shot of P. flaccida 'ABG 1998-5551' shows what a lovely habit this form has. I have not trained it or removed suckers...and this is what it has done in it's second year of bloom from leaf cuttings. The diameter of the plant shown above is just under 4 inches diameter. This plant is potted in a three ounce shallow condiment cup where it has now remained for two years.

Petrocosmea parryorum....blooming NOW?!!??

2010-09-01T18:25:00.003-04:00

"I look upon the pleasure we take from gardening as one of the most innocent delights of human life" Cicero........

One of the delights of working with plants is that one never knows what they will do..how they will perform. Just when we think we've figured out what triggers them to bloom or what they need to grow well, they fool us. I think this is my favorite trait of plants....they remain creations of nature and they remain governed by it, no matter what we as humans attempt to impose upon them.

And so it is also with Petrocosmeas and my love affair with them. Having proven and tested the hypothesis that they need cool and dry conditions to trigger bloom....my Petrocosmea parryorum has shown me clearly that I don't know anything....it is blooming for the second time in nine months and is putting up bloom at an amazingly profuse rate...at least for me.

Having grown P. parryorum for around ten years now, with no hint of bloom until three years ago, it is now blooming. The bloom is on my most mature plant..."the grandmother" of all my Pets....a plant that is at least 8 years old. We've had a hotter than normal summer here in southwestern Pennsylvania....with many days in the low 90's F. My basement has therefore also been warmer than usual. During my illness and hospitalizations back in May, the plant got quite dry, even wilted several times...once to the point that I feared I had lost it. You will note the browning on the older, larger leaves, and the "culture break" in the center leaves, which are noticeably smaller than the others. So perhaps that is what triggered this happy surprise of bloom?

Blooms on my 8 year old Petrocosmea parryorum, coming along in the heat of summer, and for the second bloom sequence in less than nine months....a happy, if not puzzling, surprise. The blooms on P. parryorum are clustered on a multi-branched pedicel...certainly one of the most "multifloral" of all Petrocosmea species..... Most produce one to five flowers per pedicel.

The multiflowered, silvery-haired, bud-packed pedicels of P. parryorum have a tight curl to them as they emerge from underneath the large leaves. I have counted 17 pedicels in total so far in this bloom cycle.

The "Grandmother" of my Petrocosmea collection, growing in the same five inch pan pot for many years now. I repot the plant every couple of years, removing some of the outer soil. replace it with fresh potting medium and reinsert it into the same pot. Here, you can see evidence of a "culture break" that occured last spring while I was ill. The plant wilted severely several times and with the resumption of good culture, has now produced a large, floriferous plant.

The same plant, pictured from above...note the younger pedicels underneath the leaves, still yet to emerge. This promises to produce a long and memorable bloom cycle for me to enjoy.

So this happy event proves that the more I learn, the less I know about Petrocosmea. Most species have only flowered once annually for me....which until now, I would have assumed P. parryorum to do also. P. parryorum has also only bloomed in winter for me previously...making this summer bloom cycle a bit puzzling. Was it the dry periods that triggered the bloom more than the cold? Is it related to the age of the plant in any way? Was it influenced by the size of the plant, and the mass of foliage, needed to support strong bloom??? Whatever the answer to the riddle, it now offers more questions for study..... but beyond all of that, it gives me pause to marvel and wonder, and thrill at Petrocosmea and Nature....... and isn't that really one of the reasons we garden anyway?

Happy Surprises... Petrocosmea 'Keystone's Whipporwill'

2010-08-23T08:04:00.001-04:00

Every day brings a surprise for the grower and hybridizer of plants. Since the cultivation and hybridization of Petrocosmea is still in it's infancy, I'm finding this genus, my favorite gesneriad genus, especially thrilling. If you have never tried hybridizing, you really must. I promise you that if I can figure it out, anyone can. I have no training in this stuff....I just started with an interest, then a fascination, then, some might argue, an obsession. I read everything I could find on the genus, (and I could find very little to read, let me assure you.) But, mostly, I observed my plants, and tried, and failed, and tried again, and failed again (repeat this ten more times....). Then finally one day, it worked! So, pick a favorite gesneriad or two (I guess to hybridize one would need at least two...)...and try it! You'll be in for an incredible journey!

So, what was today's surprise? Well, my hybrid from last year, is flowering again, only five months after it's first flowering...and it is flowering in the summer! Why am I excited about this? Well, for one thing, it shows great promise of having a Petrocosmea that will flower more than once annually....it extends the number of days in a year when the plant will be in flower! And, it extends the flowering season into the summer months...a time when, for most of us, our Petrocosmea plants are not in flower. The hybrid, pictured above, is P. 'Keystone's Whipporwill'. The parentage is P.' Asa Blue' x begoniifolia.

P. 'Keystone's Whipporwill' in its second bloom.... gets better with age. The original plant, pictured above, is growing in a three inch diameter, one inch deep condiment cup...the type used in restaurants to serve sauces, etc. The center leaves are tight and puckered due to my choice to switch my fluorescent lights to T8 bulbs about three months ago...resulting in a great deal more light...many of the Pets don't care for it. I will be reducing the hours/day that the lights are on to make the plants happier. But, other than that, the plant has performed well. It grows easily, has not suckered, so far, and has attractive deep green foliage with a bronzy/purple cast and underside. Foliage is reminiscent of the P. begoniifolia parent, but more heart shaped, and a bit softer, like the P. 'Asa Blue' parent. P. 'Asa Blue' is a remake of the cross which produced 'Momo'...P. nervosa x flaccida. It flowers several times a year, and has a high flower count. This cross marked the first success at using a Petrocosmea hybrid as a parent. So these hybrids have three species in the background.

With maturity, the pedicels are producing three to five flowers each, on the average. Prior to taking the photo, I removed six spent blossoms. There are still lots of buds coming underneath the leaves. This promises to increase the bloom count and extend the flowering season.

The lighting in the photo doesn't clearly show the attractive bright yellow stripes in the throat of the flowers...but they are there. The blue in the photo is pretty accurate. Flowers have the shape of the begoniifolia parent, and this is also where the yellow comes from. Flowers are larger than either parent too. Plant size seems compact so far.

Another characteristic that I selected P. 'Keystone's Whipporwill' for was the attractive purple flower stems and calyces. I felt that since most Petrocosmea stems and calyces are green, this added another pleasing characteristic to the hybrid. I have distributed a few leaves to close friends for testing. Now, with further evaluation, I will begin to distribute the plant more widely...guess I'd better put some leaves down for myself too...for insurance. More than two years in the works, I'm happy with the result and consider the effort well worth it!

Bigfoot....Story of a Big and Furry seedling!

2010-08-22T17:42:00.002-04:00

I have trouble even calling this baby a seedling...it's so big! The picture above shows a great example of the agonies of hybridizing....waiting to see a new seedlings full potential before deciding to keep it or cull it. Sure it's a nice plant...even a nice Petrocosmea...but I'm trying to hybridize for more than a "nice" Petrocosmea...we already have plenty of those designed by Mother Nature in the form of the various species.... At around nine inches in diameter...yes nine inches in diameter, its an impressive green plant. The result of a cross between the compact and happy little species P. forrestii, which was it's mother, and the much larger and bolder P. duclouxii (or grandiflora, depending on whose opinion you favor). It gets it's form from its mom. To look at the photo and not know the plant size, one could easily assume it was a photo of a non-flowering P. forrestii...but this guy is BIG!!! Larger, even, than it's father..P. duclouxii.

Note the furry leaves...the long silvery hairs on this plant clearly came from P. duclouxii. They are soft and silky and enhance the plant's appearance and appeal. This seedling has two named siblings...P. 'Keystone's Little Rascal' and P. 'Keystone's Angora'. ..(both of which are pictured in previous posts on the blog). It did bloom, last year. Flowers were very similar in color and size to it's P. duclouxii parent. The flower count for a first bloom seedling was very good. My records show that it produced 22 flowers over the first bloom season. The bloom season was from late January through the end of March...so it had an acceptable flowering period.

So why am I hesitant to name it? My hesitation is from two concerns....1) was it different enough from P. 'Keystone's Angora' and 2) the flower pedicels were long...much like P. forrestii. The pedicels appeared wiry and didn't hold the flowers upright at the best attitude. They did support the flowers..they didn't flop, it was just that when I looked at them...they didn't look back at me as nicely as I would have hoped. The flowers were quite large...larger than either of it's two siblings, which was a plus. The lobes, however, were sort of pointed more like the forrestii parent and I felt the rounder lobes of 'Keystone's Angora' were more attractive. The flowers on this one were more "star-like" and pointier in appearance.

So, another year of growth has shown that this seedling is different in several promising ways, and it is surely larger than it's two siblings. It shapes up nicely, and makes an attractive rosette. Lets just see what the next flowering season produces. And, of course, we'll see if it produces suckers...so far, none of the selections in this cross have done so. (I select against offset or sucker production in my hybrids, as I feel it detracts from the nice, smooth, flat rosette. The plants root easily from leaf cuttings, so I feel the suckers are not needed.)

"The Wait..." New Petrocosmea Hybrid Seedlings

2010-08-14T20:06:00.001-04:00

The miserably hot weather we've been having is not "a favorite" with my Petrocosmeas. While they much prefer the cooler temperatures of autumn and winter, the humidity that comes along with the warm temperatures does provide some comfort. As the days get hotter, I lower the number of hours that my lights are on and increase the air movement in the basement growing area. The mature plants seem to just stand still, in suspended animation, while the little seedlings actually chug along, growing at quite a rapid pace.

A few species are in bloom....P. barbata, P. begoniifolia, and even P. nervosa and P. sp. 'vittatae' are blooming. The hybrids, P. 'Asa Blue' and 'Short'nin' Bread' are also in flower now. To test my theory that successful seed set only occurs in cold temperatures, I tried to self all of the above and got nothing. I tried crossing several of them also...and got one enlarging seedpod on nervosa, for a month, then it died. They just seemed to laugh at me and my folly of asking them to do something that I was pretty sure they were not about to do....and they didn't! I have tested pollination in warmer temperatures for two summers now without success. Last year I did get three mature seedpods on P. begoniifolia, but when I opened the dried seedpods, there was not a single seed to be found. I even examined them under a microscope...no seeds. In winter, with cold temperatures, I have much greater success with seed formation.

I mentioned the hybrid seedlings. This summer I am watching a number of exciting new crosses coming along. My favorite, so far, this year, is a cross between P. forrestii and P. minor smooth leaf form. This is only the third hybrid that I have been able to produce from P. minor. The plants are making lovely deep green rosettes, similar in size and appearance to P. forrestii, but with a deep green glossiness to the leaves that is definitely P. minor!!! One seedling in particular has leaves that are very glossy.

A trio of seedlings from a cross between P. forrestii and the smooth leaf form of P. minor. The seedling in the lower portion of the photo is much glossier than it's siblings and a bit deeper green in color. From among a tray of a dozen seedlings, this one has stood out from the very early stages for the glossiness of the leaves. Note the slightly different leaf shapes and the differences in the leaf veining. The seedling in the upper right has leaves that are nearly perfectly round, like minor..... while the other two seedlings have a bit more of a point at the tip of the leaf...more like forrestii.

"The One To Watch" at least from the standpoint of foliage. This seedling of P. forrestii x P. minor smooth leaf form has leaves that are significantly glossier and shinier than it's siblings. I'm talking to this little guy every day now! The seedling in the photo is now four inches in diameter.

Back at work.....

2010-07-07T20:16:00.000-04:00

Greetings! One never knows what life is going to toss at us. The last couple of months have been a bit tough with an unexpected illness and surgery. Three hospital stays and a few weeks to recover and everything is fine now...things seem back on track. The past couple of weeks have seen me able to get back among the beloved Petrocosmeas....I've missed them~! But, as they always do, they banished my duldrums with the annual start of the flowering season. The earliest to bloom for me, P. formosa, was in all of her glory when I made my first visit back to the basement plantroom. What a welcome!

While P. formosa most typically blooms in pale orchid purple, a fellow Petrocosmea enthusiast in New York gave me a peek at his white P. formosa. Not sure where he acquired the plant, he did not recall it being given to him as a white form...however, that's what it has produced for the past couple of seasons now. He observes that the flowers remain pure white with the typical yellow base to the upper corolla lobes. I did note, that the yellow blotch in this form is more lemon yellow whereas the yellow blotch in the typical purple form that I grow is more orange-yellow. I have a large leaf form and a small leaf form and both produce purple flowers with orange-yellow blotches. I'm hoping this one remains white.... a lovely flower it was indeed!

Getting back to the Petrocosmeas just as they are producing this years flush of growth made me restless to get things groomed, repotted and "back in order". This photo shows an assortment of species Petrocosmeas in the matt-lined trays in which I grow them. The larger plants in the foreground are in 5 inch pan pots and are a couple of years old now. They were groomed of old outer leaves, the top quarter inch or so of soil was gently washed away and they were top dressed with systemic insecticide granules and fresh soil mix. The mats were washed in hot water, detergent and bleach and repositioned in the bottom of the trays, where they were dampened to provide humidity. These mats are cheap acrylic blankets cut into 22x22" sections, folded once to make a double thickness to line the 11x22" nursery trays. As the plants come into bud in the fall, the trays are covered with a plastic humidity dome to increase the humidity for the flowers....which aids is successfull pollination when I hybridize them. Last the plants were watered in with dilute fertilize water. And, for good measure, I told them how beautiful they were and encouraged them to grow up to be big and strong....

I've often been asked "How do you find new Petrocosmeas?" Admittedly, they can be a challenge to find. I am very fortunate to have great plant friends who know my love for the genus, and when the acquire new selections, the share them with me. The box above was a generous gift from a dear Canadian friend who brought them across the border to me last March when I attended the Buffalo, New York gesneriad and violet show. The included a new unidentified species labeled P. sp. 'Chinese #3' and a new form of P. rosettifolia with nice bluish lavendar flowers...(this made my fifth form of P. rosettifolia...all distinctly different from each other, but all clearly, the same species.....of course DNA analysis helped me to prove that!) How exciting to have five forms of the same Petrocosmea species! So, my advice to those wanting to build a collection is to get the word out to all of your plant friends......Gesneriad lovers are among the most generous people in the world!

Once home, I dutifully put down leaves from each of the new Petrocosmeas in the box above, partly as insurance again loss, and partly to be able to distribute them to others. That is one of the best nuggets of advice I ever got from a wise gesneriad grower.....Whenver acquiring a new gesneriad...PROPAGATE IT!!! That has saved me from losing a precious new acquisition so many times!

It feels good to be back. I'll do my best to post to the blog more often now!

Bloom Potential for Petrocosmea and "How Do I Get Them To Bloom?"

2010-05-25T16:38:00.001-04:00

What can we expect from a Petrocosmea when it flowers? How much bloom is the plant capable of? When we look at a Petrocosmea entered in a flower show in bloom, how do we assess if the plant is meeting it's potential for bloom? As an admirer of this fascinating genus, and as both and exhibitor and Master judge for the Gesneriad Society, I am often faced with these questions. When I give a presentation on Petrocosmea, I am often asked how to "make them bloom". So for the past couple of years, I've done a bit of personal research and study on my own plants to assess just what it takes to get the plants to bloom at their full potential. I thought I would share my findings and thoughts with you here.

The plant in the photograph above is Petrocosmea grandiflora (or duclouxii, or floribunda...depending upon the source you obtained your plant from...genetically, they are all turning out to be the same species). This plant is my own plant, and the photo was taken this past January, as one all five of my mature plants of this species came into flower. This one is typical of those that I grew in the basement, in rather cold conditions, with humidity between 45 and 70%. The plant is in a 5" pan pot, where it has now been for four years. I have only top dressed the plant with new soil...it has not been repotted in that time. Starting in August, this plant was given plain water, only watered about once a month, and kept rather dry in between these monthly waterings. At times, the soil dried to the point that the leaves wilted a bit. Temperatures in December and January were as low as 35 degrees F and and as high as 52 degrees F. This is it's bloom potential under these conditions. Other plants of this same species, of the same age, in the same potting mix and pot size, that were kept warmer, and given more frequent waterings, (one was wicked on a reservior of dilute fertilizer water) all flowered significantly less than this one. The plant on the reserviour of water had less than half as many flowers, but did have more leaves on the rosette.

So this is what I got with the cold, dry, humid, and no fertilizer treatment described above. Other species given identical treatment all flowered heavily. They are pictured below.....

Petrocosmea minor smooth leaf form was also kept cold, dry and humid. This is the most this plant has ever flowered for me in several years. This species does not appear to flower heavily at one time, but instead seems to flower over a longer period of time, with a few flowers open at one time. This plant is also in a 5" pot and has been there for three years now without repotting.

The above photo is a showplant, a first place winner, grown by the master gesneriad grower Bev Williams of Canada. Her plants are always grown and shown at full potential. The plant is a lavendar flowered from of Petrocosmea rosettifolia. This species always seems to put flowers out along the outer edge of the rosette, rather than clustering the flowers toward the center of the rosette as some species do. Note the flowers here....when entered in bloom, this is what an exhibitor or judge of Petrocosmea should consider in deciding on the points value of "Quantity of Bloom". Many Petrocosmeas entered into shows here in the USA in flower are in my opinion, entered as either immature plants or they have been grown in such a manner that full bloom potential is not acheived. Often Pets in shows have four or five flowers and they score pretty high on the "Quantity of Bloom" section of the score sheet. This is something that judges should begin to consider and "adjust" when the evaluate Petrocosmeas entered in bloom.....again, just my opinion........

A mature but rather small plant of Petrocosmea sp. 'China 2005' in it's third year in a 3 1/2" pot. This plant was also given the cold, dry, humid, plain water treatment described above, and flowered much better this year than ever before. This plant stays much smaller at maturity than other species, so I grow it in a smaller pot. It's bloom potential makes it a great candidate for hybridizing with the goal of producing hybrids with more bloom potential. Cold and dry seems to to the trick with this one too!

A blooming plant of Petrocosmea sp. 'Yumebutai'. I've only had this plant for three years, and it has remained in a 4" pot since I got it...never repotted. When this plant was given to me, the grower said that he'd never been able to flower it. I've also heard this about this species from one other grower. The plant did not flower for me last year, when it was grown warmer and watered more often. But, this year, the cold, dry, and humid treatment worked well. This photo was taken in early February of this year.

SO, what factors worked best for me? Well, the cold is definitely a positive factor in at least increasing the flower count. I've heard from a correspondent in China, who has seen Pets growing in habitat many times, that the plants often experience short periods where they are covered with snow. My basement gets down to the mid-30's F range. Now, I realize that most growers who grow in the living areas of their homes cannot allow the temperatures to get down into the 30's.... but I'm just saying that it definitely helped in my research. Yes, plants in the warmer areas did flower...just not nearly as much as those in the basement where it was cold.

Secondly, plain water helped. The rationale I used for this is that fertilizers might be forcing more foliage growth at the expense of flower buds. Maybe so, or maybe not. But that was a factor in my experiment and those plants did seem to have more flowers and smaller rosettes. I began with the plain water when the plants were beginning to form buds.

Third, high humidity. I feel this helps the buds to mature and not to blast. In the warmer areas, with more heat, the humidity was lower. I occasionally did see a loss of some flower buds in that situation. But, then I advocate high humidity for Petrocosmeas all year long. Why, because my plants with higher humidity look better, grow better, flower better and set seeds better than those with lower humidity. That's good enough for me!

Fourth, infrequent repotting. I won't go so far as to say that Petrocosmeas resent repotting. I've never had a Petrocosmea show any apparent negative effects of repotting. I'm just saying that I don't think it is necessary. I get great results by leaving them along. As long as the mix is draining well and not washed away, my Pets seem very happy staying where they are. Also, I'm not aware of anyone or anything in nature that repots the Petrocosmeas in the mountains of China? Are you?

Last, maturity. By that I mean that I now feel that it takes three or four years of growth for a newly propagated Petrocosmea to reach it's full potential. My plants clearly perform better with each year of life they have...my older Pets perform the best every time! So, again, when considering a show plant....is it mature? This can be difficult to tell since the grower may have kept the plant smaller intentionally, and should therefore not be faulted for choosing to do so. However, bulk seems to improve performance....perhaps the larger root mass and foliar mass support more flower production?

So there you have the results of what I am seeing as I study these plants more closely over the past few years. I hope these observations will help those who are struggling with getting their Pets to bloom......and judges!!!.....consider bloom potential when awarding a Petrocosmea entered in bloom.

"The Experiment" - Growing Pets Outdoors

2010-05-01T17:38:00.003-04:00

Having grown Petrocosmeas in just about every fashion possible INDOORS, I had to try growing them outdoors. Here's my story...........

I'm not sure if the problem was having too much time on my hands or having too many Petrocosmeas on hand, but the thought occured to me, and I just had to do it! Actually, I'm certain it wasn't the former, because there never seems to be enough time in the day.... Nonetheless, I'm now well on my way with an experiment in growing Petrocosmea outdoors in southwestern Pennsylvania. Pittsburgh is in USDA zone 6, and my outdoor growing space is pretty cool and shady. Our summer temperatures here are relatively mild, with lots of rain. As I thought about it, I realized that our climate here is pretty close to what I've read about the natural environment where many Petrocosmea species grow in China, so I figured...."why not?"

So, here's what I've done. First, I selected the plants I wanted to use a couple of weeks ago, and let them dry out to the point of being limp....I did this in order to avoid breaking leaves off of brittle, turgid plants. Then, I took an old terracotta "strawberry jar", (I've had this thing forever!!!) and filled it with a loose, but fertile soil mix that included lots of humus and a little composted manure. I selected a collection of species that offered variety. And, having groomed more than my fair share of dirty Pet leaves, I decided to fill the jar and start to pot from the top, in order to avoid soil from above falling onto the leaves of the plants below. This is backward from the way I would normally pot up a strawberry jar, but for the Pets, it worked flawlessly. And, since Petrocosmeas are "rock plants" I had to include a large rock on the top for some ornamentation and interest. The Pet species I used were : minor veined leaf form, rosettifolia forms #2, and #3, barbata, forrestii, begoniifolia, nervosa, and kerrii. I mulched any exposed soil with small gravel and watered them in with a vitamin root stimulant diluted in water. They will remain in total shade and I sited them so that they will get good air movement. Luckily the spot is also along the path I take into and out of the house each day as I go to work, so I can see my beloved Pets at the start and end of my dayI!

I'll let you know how the experiment progresses!

A Few More Baby Pictures.....

2010-03-31T18:25:00.001-04:00

Well, you know how it is with proud parents and pictures of the "kids"...... I found a few more photos from the same P. 'Asa Blue' x begoniifolia cross. The photo above shows a large flower, very full petals, a pinkish coloration and some ruffling in the petals. The slight yellow marks in the throat are still there, and this one has some spotting in the throat. The peduncles on this seedling were also nice and compact, which helped to support the large flowers. This one was also kept for further evaluation. (Sorry that the photo is not in focus.)

This photo shows the flower from the first photo, beside of a sibling which has the more typical flower shape for the cross. I took this photo to show the difference in the roundness and fullness of the petals. The leaves also has a nice purple border, which came from the begoniifolia parent. P. begoniifolia is the only Pet that I've seen that has burgundy red underside to the leaves.

The first seedling to flower....... Wow, was it a surprise and was it different! It has ruffled petals, extra petals, yellow and green in the throat, and white splashed all through the petals. It kept these characteristics in the subsequent flowers to open....but was not as floriferous as I had hoped...I have kept it for further testing...hoping that with maturity, it will prove to be more floriferous.

And one that I kept calling 'Froggy' since it has an odd shape, and lots of green in the flowers..... This flower has four colors...green, white, yellow and purple! Of course, I kept this one to test further too......

Finally, as shot showing the foliage from a seedling...this plant, 'Keystone's Belmont' (photo of flowers in the previous post), was awarded 96 points in the New Gesneriads class at the recent show in Bufflalo. It won a second place ribbon in competitive judging, nudged out of first place by my other Pet. hybrid 'Keystone's Bluejay'. This hybrid shows a bit more of the P. flaccida grandparent in it's ancestry...which is one of the parents of P. 'Asa Blue'...it's mother.

I've been quite happy with the results of this cross. The variation has been stupendous and I am anxious to see the seedlings which I have selected as they flower in the second season this fall.

Baby Pictures - My Petrocosmea Seedlings

2010-03-31T18:02:00.002-04:00

Now that spring is officially here in southwestern Pennsylvania, the sun is brighter, the hours of daylight are growing longer and the temperatures are warmer. The plants can certainly sense the changes. I am seeing strong, and rapid growth from the Petrocosmeas, as well as most of the other gesneriads. Today, I spent several hours in the basement growing area repotting seedlings, grooming last years older, yellowing leaves from the outer rows of the Pet rosettes, putting leaves down to root, and dividing those Pets that have formed offsets.

As I worked, I found myself working with the trays of seedlings from last year's most exciting cross...P. 'Asa Blue' x begoniifolia. I raised around 40 seedlings from that cross. As I worked wtih the seedlings in these trays, I was reminded of the flowers on each one as I picked them up one by one to scrutinize them and groom them. No offsets on any of them....Good!!! (I am choosing seedlings that show a reluctance to form offsets, since I feel that offset formation often ruins a beautiful showplant and spoils the flat, symmetrical contours of the rosettes.) The variation in the flowers from seedling to seedling was fantastic, and I was continually amazed at the different markings and shadings on the flowers. This cross gives me high hopes for the future of Petrocosmea hybridizing. I decided to share some photos that I took from some of the more exciting seedlings......

The photo above is a seedling from this cross. There were four seedlings that showed the extra petals in the center...which surprised me. Most flowers took the form of the petals from the begoniifolia parent, as well as showing the two yellow spots that the white begoniifolia flower exhibits. The seedling above is, so far, unnamed. I've kept it to test for another season of bloom and to test for offset production before deciding whether to name it.

There were a couple of realy odd flowers. This one shows lots of yellow in the throat as well as touches of yellow on the lower petals. I kept this one just to see what it does in the second season. The flower is not necessarily attractive, but it might be helpful in getting more yellow into the petals of future hybrids. This one also hints at striping in the petals....reminded me of chimera African Violet flowers.

I loved this one! The coloring is so delicate and the lower petals retained the greenish coloration seen here. I also liked the cupping of the petals...and the bell-shaped flower apperance. Again, I kept it, but have not named it so far.

The flowers above, were the first to show extra petals, and the deep blue coloring with the white center halo was consistent as the plant continued to bloom over a long season. Flowers were numerous and large. One additional nice thing about this seedling was that as it had finished it's round of bloom, it put up a second round of bloom about two months later...all of this on a seedling that was at that point, only eight months old. I named this one 'Keystone's Belmont' in honor of my college alma mater in Tennessee. The school's colors just happened to be blue and white also!

A trio of siblings from the cross....showing variation in coloring and shading. I kept all three of these. The one on the left was named 'Keystone's Barnswallow' in honor of the barnswallows that I remember so fondly from my childhood on my grandfather's farm.

Petrocosmea flaccida - Part II - Hybrids

2010-03-28T10:12:00.002-04:00

In Part I I discussed the two clones of P. flaccida in my collection and the history and culture of this species. In this post, I'd like to begin to showcase some of the hybrids which have P. flaccida in the background. To date, P. flaccida may be the most widely used species in hybridizing. I can recall at least five named hybrids that have P. flaccida parentage or ancestry.

The oldest P. flaccida hybrid and the oldest Petrocosmea hybrid, for that matter, is P. 'Momo', made by Nagahide Nakayama of Japan, by crossing P. flaccida and P. nervosa. The plant, for me, grows very much like a large P. flaccida and is perhaps, a bit more floriferous, with slightly larger flowers than P. flaccida.

A couple of years ago, Mr. Nakayama did a remake of the same cross that produced P. 'Momo' and released two of the resulting seedlings. Those seedlings, named P. 'Asa Blue' and P. 'Imperial Butterflies' are improvements, in my opinion, over P. 'Momo'. I grow both of them and really like them. I have been successful in using P. 'Asa Blue' in one cross with P. begoniifolia.

P. 'Asa Blue' an improvement over P. 'Momo', was the result of a remake of the same cross that produced P. 'Momo'. The plant flowers several times a year, and the flowers are large and show. The plant also shapes very nicely.

The photo above, shows the flowers of the parents of P. 'Asa Blue' - P. flaccida, and P. nervosa. P. 'Asa Blue' is incredibly floriferous and flowers are larger than either parent with improved form. This hybrid is also fertile for further breeding. Seedlings inherited it's early, free-flowering nature.

Another hybrid, boasting P. flaccida as a parent is P. 'Short'nin' Bread'. This cross used P. forrestii as the seed parent. P. 'Short'nin' Bread' is a vigorous, attractive hybrid which can be grown quite large with good culture. It flowers freely at a young age, although generally only once a year, for me.

A sibling to P. 'Short'nin' Bread', P. 'Fluffer Nutter' has the same silvery felt covered leaves, but a more compact and neat leaf habit, seeming to take this from it's P. forrestii parent. This hybrid, sadly, is not free flowering, and is the only Petrocosmea in my collection which I have never flowered, even after several years of growing. Still the foliage is attractive.

A flower from one of the selected seedlings from my hybrid cross using P. 'Asa Blue' crossed with P. begoniifolia. These seedlings have been quite free flowering at a young age. Almost all have been attractive and selections have been difficult due to the large amount of variation I've gotten from the cross. (I wanted to keep them all!) I have so far, selected five or six to grow on for further evaluation. The seedling above is unnamed at this point. It inherited a nice deep blue color from P. 'Asa Blue' with flower shape and the white /yellow throat from P. begoniifolia.

P. flaccida is a wonderful old friend among Petrocosmea admirers. If you don't grow it, you should. It's flowers are among the darkest purple of all Petrocosmea species and it is a good bloomer. These characteristics are passed along to it's progeny in hybridizing, which gives it a secure spot among our growing list of Petrocosmea species and cultivars.

The First Show of Spring

2010-03-22T20:48:00.001-04:00

The first gesneriad show of Spring! What better way to welcome Spring than to spend a weekend among plants and friends. And if those plants are gesneriads, even better. AND, if those gesneriads are PETROCOSMEAS then it's joyful indeed! I was priveleged to spend my first days and the first weekend of Spring among wonderful friends and wonderful gesneriads while attending the annual spring gesneriad show of the African Violet and Gesneriad Society of Western New York, held in Buffalo, NY. I have attended and judged this show for the past three or four years and it is always a superb time. This year was no exception.

While driving up to Buffalo from Pittsburgh, the promise of Spring was dampened somewhat when I approached Lake Erie near the borders of northwestern Pennsylvania and Southwestern New York. In the photo above, those white clouds in the background behind the vineyards are NOT CLOUDS...but the still-frozen Lake Erie!

Of course, once I arrived at the show, the frozen lake was a faint memory as the abundance of skillfully grown gesneriads took over my visual senses. I love, and grow many plants, many gesneriads too, but my heart always draws me to the Pets! The show this year has number of beautiful Petrocosmea among the entries. This year, I was able to both judge the show as well as enter some of my own gesneriads. I brought three of my new hybrids to enter in the class for "New Gesneriads". The only collection in the show, pictured above, was a spectacular collection of Petrocosmea hybrids and species grown by a master Pet grower...Paul Kroll. His collection won a first place award...not because it was the only collection, but because it also scored greater than 90 points. When exhibiting a collection, the pressure is on the exhibitor to showcase several well-grown plants that show the diversity among the plants within the genus. Pauls collection did a nice job of doing both. I felt that the choice of brown fabric complimented the green plants well.

The Petrocosmeas grown for the ornamental qualities of the foliage had a nice representation as shown here. The public was repeatedly drawn into the table with the Petrocosmea entries. For some reason, the foliar habit of Pets seems to mesmerize people.

A nice surprise this year was that an eductional exhibit entry also showcased some recent and ongoing work studying the Phylogenetic relationships of the species within the genus Petrocosmea! This exhibit was presented by a professor from Niagara University and showcased work being done there. I was quite familiar with the work as I have been honored to have been a small part of it through contributions of plant material, hybridizing data, and morphological information. The authors of the work are hoping to finish the study this year.

One of my entries, a selection of my hybrid cross between P. sericea and P. minor veined leaf form named P. 'Keystone's Bluejay' was honored with a first place award as well as selection for Second Best in Show! The comments and feedback from the judges were quite kind and welcomed. I was very excited to see such enthusiastic support and appreciation for my new hybrids. This is the only plant selected and named so far from that cross, which flowered last year. I have kept four other plants for further evaluation. Judges loved the silvery curls in the center of this plant. I was able to make several distributions of leaves from this plant, and hopefully, will see others exhibiting it in the near future.

The show had a number of spectacular gesneriads, designs and natural gardens. The artistic section of the show was especially nice this year. Petrocosmeas showed up in several of the natural gardens and terrariums this year too. It is great to see a growing interest in my favorite genus.

Petrocosmea flaccida - Part I - An Overview

2010-03-16T17:10:00.004-04:00

In this new series of posts, I decided to focus on a species that for many of us was the first Petrocosmea we grew, Petrocosmea flaccida. I want to include an overview of the species and it's history, characteristics, varieties or clones available in cultivation, it's culture, and finally it's influence upon it's several hybrids.

The photo above, taken by my friend Julie Mavity-Hudson, illustrates the obvious ornamental qualities of this species. The charming deep violet-purple flowers, which are perhaps the darkest of any Petrocosmea species in cultivation, crowing the silvery, flaccid gray-green leaves.

The photo above was taken by Ben Paternoster of his beautiful, expertly grown P. flaccida in a five inch pan pot. He sent this photo to me a few months after he had potted the plant in a shallow 5" pan pot, following a discussion where I advocated using shallow pan pots for the culture of Petrocosmea. Ben's skill as an expert grower likely contributed to this magnificent specimen much more than the pan pot did. This specimen was grown in his basement, under lights, in Long Island, NY. A beautiful example of the results possible with this species.

Petrocosmea flaccida was initially discovered in Southwestern Sichuan, northwestern Yunnan, China growing on rocks, in thickets at between 1830 and 3000 meters above sea level. Described by Craib in 1919, it is placed in Section : Petrocosmea. This section contains species considered to be among the most primitive species of the genus, based on the reproductive structures. The upper and lower corolla lobes are roughly the same length. Anthers are seperated on either side of the ovary. Flower color is deep violet purple, with small white "fang like" marks at the base of the upper and lower petals. The peduncles are thin and wiry, sometimes with a purple hue, and single flowered. The pistil of this species is also dark purple in color as opposed to the white color of most Pet pistils.

The leaves of the species are pale gray-green, covered in silvery hairs and are flaccid, hence the name. The rosette of this species tends to be very flat, and on a large plant, outer rosette leaves will droop, due to the weak petioles. After flowering, the outer leaves will tend to yellow and die off, leaving a very tight, silvery green center of new growth which tends to sit in "suspended animation" until warmer weather when a growth spurt will occur. Often, the plant will form offsets after flowering also.

Petrocosmea flaccida's flowers are among the darkest colored of any Petrocosmea species. The upper petals tend to stand upright, and the rouned shape reminds me of Mickey Mouse ears.

For many years, there was only one clone of P. flaccida in cultivation. Recently, a new collection from the Atlanta Botanic Garden has brought a new clone into our collections. The older "traditional" clone is pictured on the left, with the smaller, ABG clone on the right. The plants in this photo are of the same age and are growing in the same size pot, having been grown side by side on my light stands to test whether the new ABG clone was smaller due to culture or genetics. It remains noticeably smaller than the "traditional" clone, and thankfully, does not produce offsets as readily. Flowers of the smaller, ABG clone have less white in the base of the petals also. Flowers are about 1/3 smaller than those of the "traditional" clone. I have crossed these two clones and got very few seeds, with two seedlings that germinated. The seedlings remain too small at this point to comment on them.

The new P. flaccida clone from the Atlanta Botanic Garden remains quite small. Shown here in a three inch pot, it appears "over potted". I am hopeful that it will prove useful in producing miniature Petrocosmea hybrids.

Culture of P. flaccida is pretty much as it is for all my other Petrocosmea. I give it a cold and dry winter rest. New growth resumes in spring with longer days and warmer weather, when I increase watering and fertilizer. Both clones propagate easily from leaf cuttings. This species is on of the "deciduous" Pets...(a term I have begun using to describe those species that tend to loose outer leaves after flowering and seem to want a drier, colder rest. A central crown of small, tight, very hard new leaves develops and remains in "suspended animation", doing nothing until the warmer weather of spring, when new growth comes on rapidly. ) This trait is also seem in may of the hybrids with P. flaccida parentage.

A Glimpse of Spring and a Gesneriad Show

2010-03-16T15:51:00.001-04:00

AAhhh, those massive piles of snow are finally melted. After the snowiest month in recorded history here in southwestern Pennsylvania, I was most anxious, and happy, to be able to attend theNational Capital Area Chapter of the Gesneriad Society's spring gesneriad show this past weekend in Washington, DC at the National Arboretum. The four and one-half hour drive was worth it for the opportunity to shed the winter cold, visit with some great friends and be among a multitude of gesneriads. This chapter always has a great show, and this year was no exception. While I did not enter any plants in the show, I did help to judge the show. The quality and quantity of plants was excellent. The number of genera represented in the show was quite high also.

Of course, I always have to scope out the Petrocosmea entries whenever I attend a show. There were a few Pets entered in the "Grown for Foliage" classes, and one entry each in the "New Gesneriads" class and the "Gesneriads in Flower" class. I was reminded, as a hybridizer of Petrocosmea, how badly we need an extension of the flowering season among the new introductions. Being strongly seasonal bloomers, most Pets are in flower in the winter. Most gesneriad shows are in Spring, Summer and Autumn, so Pets are rarely seen in shows, in flower. Often, sadly, when they are shown in flower, they are not at their best. The new hybrids MUST bloom heavily, for longer periods, and during the warmer months of the year....this must be a goal for anyone hybridizing Petrocosmea.

The Pets entered in the Foliage class were only six in number, and relatively young plants. Still, a bit of variety among the genus ,and well shaped for young plants. Many of these plants shown, were grown by a younger, new member of the host chapter, who has only been growing Petrocosmea for a year!!!! He is obviously off to a great start!

One lone Petrocosmea entry in the New Gesneriads class, and the only Petrocosmea hybrid in the show, was the spectacular new hybrid, P. 'Imperial Butterflies' from Mr. Nakayama of Japan. It's parentage is P. flaccida and nervosa. This hybrid is vigorous and produces large, double flowers with ruffled petals on a mature plant. I grow this plant, and love it. The entry won a blue ribbon for First Place. This plant shown, was also grown in leca stones and hydroculture!

The most exciting Petrocosmea-related story from this show was that the Best In Show entry was a collection of Petrocosmea grown by a young man who has only been growing Petrocosmea for a year! This display was exhibited with the plants clustered on a rock..... I found this a charming way to unify a collection of Petrocosmea, since the genus name Petrocosmea means "pretty little plant on a rock". This was a collection of pretty little plants on a rock! From top row left, moving clockwise the species in this collection are: P. sp. 'HT-2', P. parryorum, P. kerrii, P. rosettifolia, and P. minor veined leaf form (exhibited as P. sp. #5). Additionally, this entry was voted by the public who attended the show as the winner of the "People's Choice Award" for the public's favorite gesneriad in the show! The public continues to love the sight of a Petrocosmea in a show. I wandered around the showroom listening to visitors to the show as they commented on the Pets. It was great to hear how excited the sight of a Petrocosmea makes people. But then, I am certainly in agreement with them!

So, keep growing , and showing those Petrocosmeas!!!!! The public demands it!!!!!

Seed Production in Petrocosmea

2010-02-25T16:34:00.006-05:00

As I continue to harvest that last seedpods from this winter's Petrocosmea hybridizing adventures, I find myself, one again, feeling excited and grateful that I've had success in producing seeds from my favorite genus of gesneriads. For years, around ten to be exact, I consistently failed to produce even a single seed..or a seedpod either for that matter. But, at least I was consistent! One of the most requested tidbits of information I receive is for advice on how to produce seeds in Petrocosmea. I thought I would outline my process here on the blog.

First, let me say that this is what works for ME, in MY environment, with MY plants. Other growers, in other conditions, may have very different results. I don't suggest that I am an expert, only that I've been lucky for a short time now, and this is what worked for me. While I have shared this with other accomplished growers in the recent past, I have heard from only one person who was successful in producing seeds. There are others, who've had success, of course. Other well before I had luck. Mr. Nakayama, in Japan, in fact, produced the first Petrocosmea hybrid around a decade ago... P. 'Momo'...the result of a cross between P. nervosa and P. flaccida. He has since remade the same cross and produced two selections..P. 'Asa Blue' and P. 'Imperial Butterflies'. Mrs. Joyce Stork, here in the US, produced introduced two hybrids a couple of years ago, P. 'Fluffer Nutter' and P. 'Short'nin' Bread' both from a cross between P. forrestii and P. flaccida. And Mr. Jeff Foerderer of the Netherlands, had produced a number of crosses recently. He registered two of them with the Gesneriad Society....making these the first registered Petrocosmea crosses. Those were P. 'Lexi' and P. 'Milan'. So we are beginning to see some success with hybridizing Petrocosmea. To date, I have been successful in producing seeds from a total of 22 seperate hybrid crosses over the past three years. Most of those, 14 of them, produced during this past winter.

So what has worked for me? Well, the key factors for me, which I have tested and proven during the past two winters, have been a combination of high humidity during flower production and seedpod maturity, and cool to cold temperatures. If either of these factors was changed or missing, I have had total failure in the crosses. Furthermore, I must say that those same two factors have been proven critical to successful seed germination as well. But first, lets get the seeds and then we can discuss how to germinate them.

So here are the steps I follow to produce seeds:

1. The seedpod parent must be flowering in high humidity...100% if possible. As plants come into bud, I enclose the whole plant inside humidity domes over the nursery trays on my lightstand shelves. Also the area should be cool...around 40 degrees F. A bit cooler is fine...I've had successful pod formation in 38 degrees F and as warm as 50 degrees, but no warmer.

2. Select flowers for pollination that are at least four days old. Older is fine as long as the pistil and stigma are still in good condition. Around the time the flower is about to drop seems the best, but the stigma is usually not receptive until around four days.

3. Select pollen from the freshest flowers you can find...freshly opened up to three or four days seems optimal. Pollen should look "fresh and fluffy" dry dusty pollen does not work for me. Frozen or refrigerated pollen has also failed to work for me too. I use a simple process of collecting the pollen on my thumbnail from the anthers so that I can see it easily. "Pack" as much pollen on each stigma as you can get it to accept.

This photo, taken by my friend and master hybridizer Dale Martens, shows the reproductive structures of a Petrocosmea flower. Note that the stigma at the tip of the pistil is purple. The filaments supporting the anthers have furry white hairs.

4. Label each flower pollinated. I use a small square of paper with a hole in the center and a small slit on one side to allow it to be slipped onto each flower peduncle. I also record the parentage and date of the cross in a manual which I keep all of my hybridizing records in. This becomes a most valuable resource later on.

This photo shows seedpods forming on P. forrestii. Note that after successful pollination, the tip of the pistil dries to just below the stigma. the ovary swells quickly and pollination will be evident in around 8-10 days after making the cross if it has been successful. These seedpods are about one month out from pollination.

5. Wait. This is the hardest part. Ripening for me has taken 60-80 days with around 64 days being the most common. I have had successful germination from seeds taken from a pod that was only 49 days old, when the mother plant began to deteriorate and I was afraid of loosing the cross. Generally, though, I wait until the seedpod browns and is just beginning to split open. Seedpods will split from the base upwards along two sides of the pod. The seedpods appear to have two chambers.

Another excellent photo taken and shared with me by my friend Dale Martens, shows Petrocosmea seeds. Viable seeds appear plump while non-viable seeds appear more linear and smaller.

6. Once the seeds are ripe and harvested, I sow them immediately. I only sow a small amount of the seeds and freeze the rest. I sow seeds on moist, fine vermiculite or moist peat moss pellets. I enclose the seeds once planted and keep them moist with high humidity. In the same temperatures used for seed production...around 40 degrees F, I get germination in 14-28 days from fresh seeds. Once seeds are a bit older, I find germination takes longer, and it has taken as long as 3 months on older seed. Seeds sown in warmer temperatures have consistently failed to germinate for me and several other growers with whom I've shared seeds for testing.

Once seeds germinate, I begin to fertilize them with a weak solution of water soluble fertilizer at a rate of 1/8 - 1/16 teaspoon per gallon of water. I keep them under lights in the same conditions the mature plants grow in.

Once the seedlings are large enough, I transplant them into community pots and treat them just like the mature Petrocosmeas in every way. Of course, labeling and careful record keeping are maintained at every step of the way. The photo above shows seedlings at about three months from germination.

Again, cool temperatures and high humidity are what have made the critical differences for me. I hear often from growers who have tried repeatedly to cross Petrocosmea and failed. When I ask about the conditions in which they attempted the crosses, one or both of these factors always seems to be missing.

This year, I tested this several times by attempting crosses in lower humidity and in warmer conditions. I had NO success. Only when both factors were present did the crosses take. Even then, with the two critical factors in place, my success rate with total attempts remains under 50%. I make sure to pollinate around ten to twelve flowers each time I make a cross. Sometimes I get as many as 7 seedpods, other times, I may get only one. And of course, sometimes I get none. But, the challenges are what makes this so much fun and so rewarding once those seedlings finally do bloom. This is part of what fuels my passion for these magnificent creations of nature! One thing that alway occurs 100% of the time though, is that I learn something every time I try a cross. And I have fun 100% of the time too!

A Silky Haired Trio - The Petrocosmea sericea Group - III

2010-02-08T17:35:00.003-05:00

Should our trio become a quartet? In the last two posts, I have been discussing the three plants that I place with a group I call the "Sericea Group". This is my own placement and terminology around the three plants labeled P. sericea, P. sp. 'HT-2' and a newly collected plant labeled P. sp. ?'JR2008-1'. But, should this trio include one more plant? Study the photo below in comparison to these photos of the flowers on these three plants from my last post.

Very close isn't it? I think so. Morphologically, the flowers and foliage of the plant I acquired last year labeled P. cavaleriei are so very close. I have sent plant material to have it's DNA studied in relation to the DNA of the other three, but do not yet have results. Hopefully those will come soon. But, independent of the DNA data, I feel this plant belongs to the same group as the other three. It does not totally match the published description of P. cavaleriei, but then neither does P. sericea.....or most other Petrocosmeas which currently bear a name. Again, the identity crisis for this genus.
The flowers of P. cavaleriei closely match those of P. sericea and the others in the "Sericea Group". It clearly fits within the Section Anisochilus, as do the other three plants. Other than form of the petals, it is identical.

Petrocosmea cavaleriei pictured above, looks very much like P. sericea, and P. sp. 'HT-2'...especially the latter. It differs only in it's small stature. This plant stays small, after two years, this plant still remains in a three inch pot. Cymes are single flowered. I'm anxiously awaiting the DNA results to see how closely it is related to the others in this group.

I thought I would conclude by showing a bit of what P. sericea is capable of as a parent in hybridizing. My very first hybrid, pictured above, is the result of a cross using P. sericea as the pollen parent with P. rosettifolia #3. The hybrid was named for a dear friend, P. 'Rosemary Platz'. It inherited a heavier leaf substance, the leaf shape, and size from P. sericea. Flower size and coloration on this hybrid also show the influence of P. sericea. The serrated leaf edges, the glossy green leaf color with lighter yellowish veins clearly came from the P. rosettifolia parent.

A close up of the flower of P. 'Rosemary Platz' shows a nice lavendar color from P. sericea, while the absence of the dark purple blotch at the base of the tube, along with the two yellow stipes are from the P. rosettifolia parent. Flower size is similar to P. sericea.

A trio of first flowers from three seedlings resulting in my second P. sericea cross. This time P. sericea was the seed parent with pollen coming from P. minor veined leaf form. The variation in the purple color of the flowers shows the lightest being the color of P. sericea and the darkest coming from the deep purplle of P. minor. Two flowers have the white throat of P. minor, while the one on the left has no white in the throat...which is most like P. serice. All three inherited the deep purple blotch at the base of the corolla, which both parent have. Genetically, P. minor and P. sericea are closely related to each other. None of these seedlings have been named as yet, but the three pictured are held for another years growth to evaluate their perfomance as they mature. While P. sericea can be slow to mature, these three all bloomed as tiny plants in one ounce pots.... each seedling flowered with fewer than ten leaves.

A Silky Haired Trio - The Petrocosmea sericea Group - II

2010-02-08T17:12:00.003-05:00

In the last installment, I discussed the foliar characteristics of the trio of plants I call the "Sericea Group" due to the fact that they all share very similar foliar and floral characteristics. In addition, recent DNA data shows all three plants to be closely related to each other, so close, in fact, that they may be simply three unique individuals within the same species.

In this post, I would like to focus on the characteristics of the floral morphology. I'll start with the first plant to come into culitivation... the plant we currently grow as P. sericea.

The flower of P. sericea shows characteristics which clearly place the plant within Section Anisochilus, having shorter upper petals, one half the length of the lower petals. The flowers typically have five petals, with the shorter upper two petals being fused into a two lobed "hood" which bend forward over the pistil. The anthers cup together to form a "beak" with the pollen ejecting from the pointed tip of the "beak" when pressure is applied to the wider base of the anthers. P. sericea's flowers are usually born singly on the cyme, with a nice bluish lavendar color. At the base of the tube inside, is a darker purple spot. The petals on P. sericea are a bit longer and narrower in the lower portion of the corolla.

The cymes of P. sp. 'HT-2' are often multi-flowered...having from 1 to five flowers...most commonly two or three flowers. The petals on the flowers of this form are shorter and rounder at the lower portion of the corolla, giving a "fuller, rounder" look to the flowers when compared to P. sericea's flowers. Coloration is identical on the two forms.

The lower three petals of the flowers of P. sp. 'HT-2' are rounder and shorter than those of P. sericea, giving the flowers a fuller appearance. In this photo, you can barely see the darker purple spot at the base of the corolla around the ovary of the pistil.

While my own plant of P. sp. ? 'JR2008-1' has not yet flowered, this photo shows the plant from which my plant was propogated. The calyx lobes on this form appear hairier and more silvery, when compared to P. sericea and P. sp. 'HT-2', but the flowers otherwise appear nearly identical. Like P. sp.' HT-2' this plant appears to have multiple flowers on each cyme. This photo also shows the more open form of the rosette on this form and also that the leaves are softer adn have a less succulent nature than the other two forms in this group. The leaves are more pliable and softer to the touch.

A close up shot of the cyme and flower of P. sp. ? 'JR2008-1' shows the longer, more silvery calyx and cymes on this form...an attractive feature in my opinion. I look forward to the flowering of my plant, which so far, has been slow to flower.

While the flowers are very similar, there are key differences which allow each form to be identified as unique in it's own right. Still, I feel these are all representative of the same species. Time will tell.

There is one last installment in this series....... Should Petrocosmea cavaleriei be included in the "Sericea Group"?

A Silky Haired Trio - The Petrocosmea sericea Group - I

2010-02-08T16:14:00.002-05:00

In my continuing quest to know the genus Petrocosmea better, I've been focusing lately on a trio of plants that I call the "Sericea Group". Why do I call them this? Well, because these three plants are yet more of our wonderful Pet species which are currently victims of the identity crisis that plagues this genus. Only one currently has a species name attached and even that one may be incorrectly attached to this plant. That species, Petrocosmea sericea (pictured below) is the first of the group to come into cultivation in the USA, and this is the name applied to it from that time until today. So, I use that one,being the first and the only one with a species name, as the species around which I "lump" the other two plants...those being Petrocosmea sp. 'HT-2' and Petrocosmea sp. ? 'JR 2008-1'. These three plants are the focus of this short series.

So, what do I know about these three beautiful species? Well, the do all appear to be very closely related to each other....perhaps even three forms of the same species. The early DNA analysis does place them very closely related to each other, but three clear distinct individuals. In other word, they are not the same individuals...the DNA is a bit different, but they may be the same species. My personal opinion is that they are. Morphologically, they are very close also.

Secondly, they do appear to fit within the Section Anisochilus of the genus. Morpholically, the flower's anthers and corolla easily fit the defining characteristics to fit within that section. This section also includes the plants we currently grow as P. rosettifolia, and the P. minor (s). If you grow all of these, think about the flower structure and you can easily see that aside from size and color, the flowers are shaped almost identically in may respect. These all have the two upper petals that are shortened and bend forward, fused into a "hood" at the top of the flower. The flowers of the plants in the "Sericea group" all are nearly identical, with the only differences being that sp. 'HT-2' has a branced cyme with 1-5 flowers per cyme, while P. serciea most often has a single flower per cyme. I have not personally flowered the P. sp. ? 'JR 2008-1', but have seen photos of the flowers, which appear almost identical to the flowers of the other two species. All three plants have silvery hairs on the calyx lobes and cyme, making it appear silvery, frosted and silky.

Third, the leaves of all three species are similar, with the following differences. P. sericea has the most succulent leaves of the three plants, with the margins curled up forming a "spoon", which to my eye, is very attractive. The margins of the leaves of P. sp. 'HT-2' curl downward
in the opposite manner of the leaves of P. sericea, and are a bit smaller than the leaves of P. sericea, but are otherwise identical. The leaves of P. sp. ? 'JR2008-1' are the "thinnest" and softest of the three, and are clearly the largest of the group. They are softer to touch and more flexible. The "silkiest" if you will. This form also forms the most "open" rosette of the three plants. All three plants offset rarely for me, and tend to grow slowyly. The newest of the three.. sp. ? 'JR2008-1' grows the slowest of all. The plant pictured below is now nearly two years old and still is a small plant.

Petrocosmea sericea - the first of the group to come into cultivation around 2003. It is "close" to the published description of this species, although the published description mentions the hairs being golden or yellowish... the hairs on this plant are clearly silvery and "white". Otherwise the description is pretty close. I have to wonder if the description might have been written using dried or preserved plant material to describe, and perhaps the hairs turned more yellow or golden with age and drying? I have collected some leaves to press and dry in order to see if the colors of the hairs changes with age and drying.

The leaves of this plant cup upward and are the heaviest substance of the three...being quite succulent. This plant grows slowly, compared to all other species I grow, and makes a spectacular rosette as it ages. Two years, minimum, seems required to get a "mature" plant from a leaf propagation. The plant only gets better and flowers more heavily with age.
It also tolerates and seems to appreciate a bit of drying between watering and the leaves spoon more and look more silvery with higher light.

A comparison of two mature plants of P. sericea and P. sp. 'HT-2'...both of these plants are in 5" pan pots and are three years old when this photo was taken. They were grown side by side with identical culture to test the differences in the two species. Note that P. sericea, (left) is more silvery in appearance and the leaf margins cup upward forming a spoon. The leaves of P. sp. 'HT-2' (right) are greener in appearance and the margins are flat or curl downward. Leaf size is close, with the leaves of P. sp. 'HT-2' being a bit smaller on the average.

The newest species in the trio is one labeled P. sp. ? JR2008-1'. It came to me from a friend who got it from the collector in China in late 2008. This plant grows slowly. The plant in the photo above is two years old, and is still in a 3.5" pot. It has not yet flowered for me, but I have photos of the flowers which I will post in the next post on this group. The plant in all respects is very close to the other two morphologically. Leaves are much larger than the other two plants, even on this young plant. I currently have six smaller plants that were propped from this plant as "insurance" and to share with other Pet friends so that we can begin to get this form into broader cultivation. I am also sending a plant to a botanical garden as part of the collection there. It is always exciting to get new genetic material and new forms of Pet species in cultivation.

This photo shows the leaves of the three forms discussed in this post, for comparison. They are (Left to right): P. sericea (left), P. sp. 'HT-2' (middle) and P. sp. ? JR2008-1' (right).

These three plants add beautiful and interesting diversity to the family Petrocosmea in any collection. There is no other Pet that has the characteristics of these three. While P. nervosa and P. flaccida also have the silvery, silky hairs covering the leaves, the flowers of these are quite different. P. flaccida and P. nervosa have floral characteristics that place them within Section Petrocosmea of the family, while these plants clearly fit into Section Anisochilus. Additionally, the DNA data suggests that these three plants are very closely related to the group of P. minor(s). The"minors" are their closest relatives, according to the DNA. I have been successful in crossing P. sericea with P. minor veined leaf, when P. minor would not cross with other species. This willingness to hybridize with the minors suggests a close relationship also.

In the second installment on this topic, I will focus on the flowers of these three plants.

Petrocosmea Hybridizing - Harvesting Seeds

2010-01-31T10:52:00.002-05:00

Having tried to successfully pollinate Petrocosmea flowers hundreds of times over a period of tens years, it is difficult to describe the joy of being able to say "I'm harvesting Petrocosmea seeds today!" This is my third annual seed harvest and the crosses this year have me excited about the potential for attractive, new foliage and flower characteristics...and maybe even some new colors or at least new "shades" of color. This season, so far, if my counts are accurate, I've applied pollen to 323 flowers. I've collected 21 seedpods so far, all with seeds inside, although some had a precious few seeds. I accuse me of being a bit of a fanatic about Petrocosmeas, I guess. But it is harmless fun and very exciting. I'm learning so much about this genus.

So what am I learning? Here are some observations about hybridizing Petrocosmeas and successful seed set. First, I must say again, that for me, the two key factors in my success, I believe, are making the crosses and allowing the flowers and seedpods to develop in cool temperatures (cold by some definitions) and high humidity....(100% if I can get it). Most of the failures this year, also served to prove this point for me. The early bloom season this year began in summer, when we were quite warm. The plant room was in the mid-70's F. The plants were growing out in the open shelves with the humidity at about 60%. All of those attempts failed. I did get seedpods to form on some P. begoniifolia flowers that were covered, but again they were growing in warm temperatures. All of those seedpods were empty when they ripened. As the plants continued to flower, and the temperatures began to drop with the arrival of autumn, I did not begin to have success until November 29, when I made several crosses in temperatures in the 40's F and most all took! These plants were all enclosed inside my humidity domes, so humidity was 100%. Since then, with the cool temps, I've had nearly 90% success with all species EXCEPT the P. minors...which still refuse to be seedpod parents. I have limited success with this species as a pollen parent and got one more cross this year with P. minor veined leaf form as a pollen parent onto the species P. rosettifolia #3. That was it. Excluding this species, I'm now having excellent results with high success rates if I observe the rules above.

In the photos above and below, you see the seedpod of Petrocosmea rosettifolia #3, which I feel in many ways, is the showiest of all of the forms of this species. The seedpod ripened in 62 days and was FULL of seeds, which can be seen in the second photo below. The seeds are large and plump, so I'm hoping they germinate! This exciting cross using P. rosettifolia as the seedpod parent and P. minor veined leaf form as the pollen parent, was made in the hopes of getting the darker green, and bright yellow veining of the leaves of P. rosettifolia #3 crossed onto the highly glossy, deeply veined leaves of P. minor veined leaf form. Also, I'm hoping that the purple flowers of minor will get some of the deep yellow in the throat of P. rosettifolia #3. I'm also hoping the ease with which P. rosettifolia #3 accepts pollen and sets seed will come through in fertile progeny to be used for further breeding. Who knows what I'll get, but then, therein lies the fun of hybridizing!

A bountiful seed harvest from P. rosettifolia #3. Other forms of this species are reluctant to hybridize or self. This form is almost always successful as a both a pod and pollen parent. Note that the seedpod splits along opposite sides from tip to base.

The large, showy, snow white petals of P. rosettifolia #3 surround a bright lemon yellow throat. Happily, it is a great parent. Flowers on this form are the largest of any form of P. rosettifolia.

The mother plant of the seedpods shown above. This photo was taken on the day that I began to make crosses with the plant. I'm hoping that the deep green, yellow veined, and glossy leaves come through in the hybrids. This form also is reluctant to form offsets, whereas other forms of the species form them quite readily. Flowers are large and showy, and present in an attractive fashion over the well-shaped crown of leaves....In many ways, a perfect parent for hybridizing.

The pollen parent of the cross which produced the seedpods above. This is the flower of P. minor veined leaf form..... a fragrant flower! This species has consistently been reluctant to serve as a pod or pollen parent with other Petrocosmeas, or it's siblings, or when selfed. It just doesnt' want to cross. Likely, the problem is that I have not yet discovered some peculiarity about it's fertility. You can bet that I'll keep trying. It has been successful as a pollen parent only twice before....crossed onto P. sericea, P. forrestii, and now P. rosettifolia #3. I'm hoping that the latest cross will infuse some yellow into the clean white throat of this flower for some tricolored flowers in the next generation. If it passes the fragrance along, I'll be happy with that too!!

Other things I've learned..... Petrocosmea crosses seem to take a minimum of 60 days for seedpods to ripen. A couple of crosses have taken up to 80 days to ripen. The two top species for successful crosses have been the prolific little P. forresttii in the number one spot, and P. rosettifolia #3 in the number two spot. P. sericea and sp. 'HT-2' would be in the number three spot. All of these have been successful in most all of my attempts to use them as parents. This year, I tried P. parryorum, which bloomed for me with lots of flowers. Not one attempt was successful, and I tried! Believe me I did~~!!! Attempts to use P. parryorum as either pod or pollen parent were all unsuccessful. The pollen was often rotted. I'm wondering now, if perhaps this species does not like the high humidity to pollinate? I'll be trying again next year with plant in both the uncovered and covered areas to see if by lowering humidity I preserve the pollen and maybe have some success? P. kerrii was also unsuccessful, in all but one attempt. Again, little P. forrestii came through for me and produced two tiny seedpods with a few seeds....Now if they will only germinate. P. begoniifolia seems to be the most flamboyant species for producing full, round flowers, with nice ruffling and coloration on the petals. I've used it in several crosses this season in hopes of some breakthroughs in the flowers.

One last observation that I'll mention about hybridizing. Use flowers that have been open for at least four days. It seems to take that long for the pistil to enlongate and the stigma to be mature and receptive. I've gotten to the point that I can tell by looking at the stigma when it is mature. Use pollen from freshly opened flowers, as it seems to lose viability quickly in the high humidity. But, it loses viability much quicker in the low humidity...high humidity rots it, low humidity dehydrates it. I tried storing it in the refrigerator and the freezer...so far, no success using stored pollen.

SO, a fun day, harvesting seeds and getting filled with the anticipation of the new Petrocosmeas to come along as these seeds begin to grow and show their stuff! Stay tuned.......

And you MUST try hybridizing!

Winter's Wonders

2010-01-20T16:54:00.003-05:00

Winter is a beautiful time of year here in southwestern Pennsylvania. The icy scene outside the window of my upstairs sunroom from a couple of weeks ago as we were under the effects of one of the coldest periods in the area since the 1700's is a testment to the wonders of nature. (The largest of those icycles are over 5 feet long!) While the temperatures dipped outside, I have been using the time to work with my gesneriads inside. It was a great excuse to stay indoors and enjoy those other wonders of nature - Petrocosmeas!

I decided to post some random comments about what was going on in the plantroom. While we are squarely in the middle of winter here, I am seeing the final days of the flowering season for the Petrocosmeas. This has been an atypical season for flowering this year. Usually, the Pets begin flowering for me in October and conclude around March. This year, they began flowering in early August! P. barbata, as usual, was the first to flower, and P. duclouxii and P. sp. 'Yumebutai' are rounding out the season as the last to flower...again, it is typical that these are the last, but they are much earlier than normal. We had a cooler and wetter summer, much cooler and wetter, last year, so I feel that the lower temperatures during the summer triggered an earlier season for the Pets.

The last of the seedlings from the P. 'Asa Blue' x begoniifolia cross are now blooming. The one above I had pulled out of the batch and named P. 'Keystone's Whipporwill'. It produces a large flower, with wide petals, giving the flower a nice, full appearance. The petals have a ruffling and notching that I find different and pleasing. This photo actually shows the color accurately, but the focus is poor...I apologize. The photos with better focus had the coloration all wrong. Many of the flowers show extra petals too, as does this one. I am evaluating it another year or so, and will perhaps release it if it meets my two main criteria....heavy flower production, and a reluctance to form offsets. So far, it looks quite promising. The negative is it's long peduncles, from the 'Asa Blue' parent. It was grown in low light this year, so I hope that with better light, they will be shorter and heavier. They did always support the large flowers, so that is good, but I just wish they were a bit shorter for a neater presentation of the plant as a whole when in flower. We'll see what another year of growth and another flowering season does for the plant.

Another species that tends to bloom later in the season for me is P. forrestii, seen above. This species has, for two years now, been the easiest species to use as a seed pod parent. So, if you want to try your hand a hybridizing...start with this species! So far, only two attempts to use it as a seedpod parent have failed. It has worked with species that would not cross with anything else. It's a prolific little species! It's positive qualities for hybridizing are it's neat, compact, perfectly symmetrical leaf habit. It forms a perfect, round, flat rosette. It is also very floriferous, over a long season, and flowers at a young age...all good traits for hybridizing. It's primary negative trait is the long, weak, wiry peduncles. They tend to get long and often form a tangled mess when the plant is in heavy flower. It has been recessive for the flower shape and the yellow blotch on the lower petals...neither of these qualities have shown up in a single seedling! It is dominant for the leaf shape, and the perfect symmetry of the rosette. Thankfully, those long, weak peduncles are about 50/50 in the progeny.

Finally, I thought I would throw in a couple of photos the "other" gesneriads! I actually DO grow gesneriads other than Petrocosmea! I have quite a large collection of other species from various other genera within the family. A couple of nice, uncommon species are in flower now.

Columnea raymondii is showing it's very first open flowers for me. This species is fairly new to my collection. I have always been a fan of the upright Columneas. This one came into my collection as a small cutting last July. It has been growing nicely on the windowsill of the upstairs sunroom, where it gets both eastern and southern exposure. I wish you could see these flowers! They are dramatic, striking, and very large...at least they seem large to me. The flower above is about four inches from base to tip. The petals are a deep, glossy bright maroon/red color with a very heavy substance. The outside of the petals and the tube are greenish yellow. The flowers are underneath the large green red-veined leaves. If you can find this one, you MUST try it!

And last, but certainly not least....a coveted plant for me. I've been trying to find a source for the species Smithiantha aurantiaca for more than ten years...with no luck. When I mentioned this to a friend last spring, she promised to bring a plant to me at the Gesneriad Society Convention in the past July. The first thing I did was to remove a leaf and put it down to propagate. From that leaf I got three more plants. Now, I had insurance! The original plant went into a four inch pot under the lights on the light bench, and was wicked into a reservior of dilute fertilizer water and never allowed to dry out. It grew quickly into a large plant with bronze leaves covered in rusty red hairs. A couple of months ago, the first buds began to appear on a tall, upright central spike. The coloring of the flowers is nearly impossible to capture, but it is intense. This plant is the first thing my eye goes to everytime I enter the room. The blooms seem to be illuminated from within...a bright, cheerful orange color with red spots inside the throat. I'm so happy to have this rare beauty in my collection. I've been attempting to self pollinate the flower, with no success so far...perhaps that explains it's rarity. I'm hoping that it produces lots of scaly rhizomes, but as I said, I am also having good luck propagating it from leaf cuttings. Again, a must have if you ever have the chance to grow it.

So, even with the cold, crystalline, wintery world outside, my home is bright, colorful and filled with it's own versions of the "wonders of winter". I hope that yours is too!

Good growing!!!!!

A New Year and New Discoveries

2010-01-01T18:46:00.003-05:00

First, I have to say Thank You! to all of those who have read my blog this year! I cannot express how much I appreciate the comments I've received about it from many of you. It was a bit of a self-indulgence on my part, but I hoped that it would find an audience among others who loved Petrocosmea as I do, and that it might be helpful for those who are learning about them and wish to know them and grow them better...as I do. Today, after only four months the blog has had over 900 visitors from 34 countries. I am amazed!! It has been a lot of fun to put together and I will forever be appreciative to all of you for reading it. I hope that 2010 is a wonderful year for all of you!

The new year is bringing still more new discoveries for me about Petrocosmea. First, the one species which I have found the greatest challenge to flower, finally is beginning to flower! What a great way to start a new year and a new chapter of exploring the wonders of the genus Petrocosmea! Petrocosmea sp. 'Yumebutai' came into my collection as a gift from a great friend and expert Petrocosmea grower, Paul Kroll of East Aurora, NY. This plant was first grown by a grower for the Yumebutai Nursery in Japan and was given to an accomplished gesneriad grower, Mr. Toshijiro Okuto. Mr. Okuto then gave the leaves to growers here in the USA and one of them was Paul. The plant appears as a large form of one of the Petrocosmea rosettifolia group, and initial DNA studies are showing that it is a close relative to that group. Leaves are quite thick and have a heavy substance. They are deep forrest green, with a lighter center. The hair on the leaves is bristle-like and stiff, giving the leaves a very rough texture. The leaves, for me, have not gloss to them, the have a dull appearance. Leaves tend to cup downward.

As I said, it has been a reluctant bloomer. Blooms are quite unique....the resemble those of the rosettifolias, but have only four petals as opposed to the usual five. Flowers are purple, with a creamy white throat. The two upper petals form the typical short hood of members of the Section - Anisochilus. Peduncles are purple, with up to five buds each. It is forming lots of buds, so it appears it will be floriferous. Mr. Okuto's photo of a plant in bloom does show a heavily-flowered plant, however, I cannot see the flowers well enough to determine petal count. I have not used it in hybridizing.....YET!

Petrocosmea sp. 'Yumebutai' finally flowers. Bud and bloom count appears to be high. Flowers have only four petals, making them appear elongated.

Another surprise came this morning, very early, as I went down to the plant room in my basement to check on the Pets. I have been growing two plants of P. minor veined leaf form under humidity domes, in preparation for using them for hybridizing. This morning, as I lifted the dome from the tray, a spicy floral fragrance wafted up from the tray! WHAT? A fragrant Petrocosmea?!? Sure enough, several more "sniffs" of the flowers confirmed that they were indeed quite fragrant. I then began to smell other Petrocosmea in bloom. I also detected a similar, although fainter fragrance on P. sericea. A seedling from a cross between P. sericea x P. minor veined leaf form also has a mild fragrance. Admittedly, I have never checked for fragrance on the flowers of Petrocosmea, so had not noted it before. I will be checking more Pet flowers in the future. If you have these species in flower now, you must check them for fragrance. I suspect that the fragrance was intensified by the humidity dome covering the tray, but I could still detect it later in the day after the tray had been uncovered for a while. A new discovery!

Petrocosmea minor veined leaf form....the flowers of this species have a spicy floral fragrance...at least to my nose. If you have this species...give it a sniff!

Last evening, as I was examining some dissected Petrocosmea flowers under a microscope, I noted that the flowers of P. rosettifolia #3 had four stamens. Most Petrocosmea flowers have two stamens and two staminodes...or no staminodes. This species clearly had four. I checked the flowers of P. rosettifolia #1 and #4 and they two had three or four anthers each. I then went back to double check flowers of several other species...begoniifolia, flaccida, duclouxii, minor, sericea...all of these species have two stamens. What does this mean? I don't know. But it found it interesting. The stamens of rosettifolia constrict to form a "beak" as the anthers are all attached to each other. This is a trait of the species in Section - Anisochilus.

I have sketched the flattened flower of P. rosettifolia #3 below to show the arrangement of the four anthers...pardon my rather crude artistic skills.

A quick sketch of the flowers of P. rosettifolia #3 shows the four stamens encircling the base of the ovary and pistil. The filaments on this species are often crooked with an "elbow" at the midpoint of the filament. The filaments of most other Petrocosmea species are straight.

Last, I would like to honor and pay tribute to a dear friend to all who love gesneriads.....Frances Batcheller. Sadly, in November , 2009, we lost Frances at the age of 96. I was honored to have met and become friends with Frances in 2000 when I attended my first Gesneriad Society (then the AGGS) convention in Tampa, Florida. I had read articles by Frances Batcheller for years. She was a self-taught botanist, and form many years, was THE expert on them. Frances was also an active and accomplished hybridizer of gesneriads and established the judging program for the Gesneriad Society. She was the first Judges Chairman of the Society and many judges remember judging with Frances and learning from her. I was so excited to finally get to meet Frances face to face. We became friends and exchanged letters by mail for several years after that. She always treated me as if she'd known me for years.

Frances Batcheller, in earlier years.

Touring the showroom of the 2000 AGGS convention with Frances Batcheller. I tried to absorb everything Frances said...when Frances spoke, everyone listened!!!!

While at my first Gesneriad Society convention, I won the coveted "Tour of the Showroom with Frances Batcheller" ....an traditional item in the live auction. I wasn't going to pass up the opportunity to "learn from the Master". I still recall trying to absorb every word Frances said about every plant she discussed as we toured the showroom. Frances had a knack for summing up the key points about any exhibit in the gesneriad show with a few, well-chosen words. She had a great sense of humor and was such a wealth of knowledge about every plant. The thing I admired about Frances was that on the rare occasion when she encountered a gesneriad that she did not know, she would turn and immediately admit that it was a new plant to her and she would begin to ask questions about it from anyone who she thought might know the plant. She was always eager to learn more about gesneriads. She always said that a good judge should not fault the exhibitor for the judge's ignorance about a plant.

As Frances' health began to fail in the last few years, a convention never felt the same without her. Frances taught me that I should always strive to learn everything I could about the gesneriads I love. I think of her often as I work with and study my gesneriads. Rest in Peace, Frances.

Angora and a Little Rascal

2009-12-30T05:49:00.001-05:00

With the flowering of each new cross, I get more and more excited about the potential for hybridizing within the genus Petrocosmea! I often think back to what it must have felt like for those very first hybridizers of African violets and then reflect upon the myriad of flower and foliage variations available today within that genus. Looking at a collection of species Saintpaulia, one might never imagine the variety that would have evolved from those charming, but fairly simple and uniform flowers and foliage types among the species in that genus. Oh, the things that are yet to be within the world of Petrocosmea!!!!! ( I can dream, can't I???)

The subject of my current adoration is the offspring from a cross between P. forrestii (as the seed parent) and the magnificent, and quite unique P. duclouxii. Both very different from each other in a number of ways. I was on Cloud Nine when I saw those seedpods developing! Now, ten months later, the babies have grown up and are showing first flowers. I've selected two from among the twenty that I flowered to name,and one other one which is remaining unnamed for the moment. P. duclouxii was clearly dominant form flower type in every seedling. P. forrestii was dominant for foliage type among all but one of the seedlings. Flower size was a mixed bag, with about nine having smaller flowers like forrestii and 11 having larger flowers like duclouxii. Peduncle length was clearly influenced more by forrestii...which I was not so happy about. Now, here are the "kids"........

Petrocosmea 'Keystone's Angora' was the first selected and named. It was chosen for it's magnificent foliage, which appears as a large P. forrestii, but the leaf texture is outstanding. I wish you could touch the screen and feel these leaves! They are literally as soft as angora! I HAVE to pet them everytime I see this plant. Hence, the name! The plant is showing more buds to come. I'm hoping for a bit more bloom with maturity, since both parents are quite floriferous.

The flower of P. 'Keystone's Angora' ...a smaller version of it's P. duclouxii parent, but a bit pinker, due to the influence of forrestii. Petals are rounder and more obtuse on the tip, making the flower less "starry" than those of P. duclouxii. Anthers are deformed, producing no pollen, but the pistil appears normal. I'm hoping it will be seed-fertile.

The second seedling names is P. 'Keystone's Little Rascal'. Leaves are more like duclouxii in shape and texture, with some veining, but size of the foliage is more like forrestii. It was chosen for it's heavy flower count and small size. It was the only seedling to inherit the shorter, sturdier peduncles of P. duclouxii. All other seedlings have the long, unruly peduncles of P. forrestii...and undesirable trait in my opinion. This plant did form two offsets, which I was not happy about, however, it's positive qualities of heavy bloom count, peloric flowers, most with extra petals, and the sturdier peduncles won out. The flowers on this plant are quite small, among the smallest of all it's siblings. I'm happy with it's reduced size and compact habit.

Most of the flowers (92% of them) were near-peloric and had extra petals. Again, as with all of the flowers in this cross, the anthers are deformed and produced no pollen. Pistils appear normal.

One other trait from this cross which I was very happy about, was that it produced three very small, almost "miniature" seedlings. This is the third Petrocosmea cross, involving larger parents that has show a tendency to produce a few "miniatures". My first cross, P. rosettifolia #3 x sericea produced one miniature plant, which pure white flowers (P. 'Keystone's Bantam'). By using P. 'Kesytone's Bantam' in a cross with P. forrestii (the most compact of the species), I got 100 miniature seedlings...all MUCH smaller then 'Keystone's Bantam'. None of these have flowered yet, after 11 months, and most all are producing HEAVY offsets, a trait which I am attempting to select out of the hybrids that I release, so I am not sure that I will ever release any of these. These miniatures do, however, give great hope to me that miniature Petrocosmeas are a real possibility and likely not too far in the future. Just one more exciting and mysterious trait tucked away within the genetics of this genus.

A photo showing the difference in the size of the flowers of P. 'Keystone's Little Rascal' (on the right) and one of it's siblings....(which I have not named so far). Both of these are smaller than the parent P. duclouxii. Petal shape, petal width and length all were quite variable, as can also be seen in the photo The petals of the larger flower on the left are more oblong and narrow, giving the flower a more "star-like" appearance. The petals on 'KLR' on the right are shorter and more ovoid in shape, making the flower appear rounder and fuller.

And, as must be done, the remaining 17 seedlings all went into the trash bin...... Rest In Peace!

A "Child" Grows Up... Petrocosmea 'Rosemary Platz'

2009-12-28T20:00:00.004-05:00

In a recent post, I promised that I would post a photo of my first named hybrid P. 'Rosemary Platz' as it came into full bloom this season. This was the hybrid that heralded the beginning of what has been an incredibly rewarding, enjoyable, and educational experience for me. It happened by accident, really.

A couple of years ago, after having tried for nearly ten years to get Petrocosmeas to set seed, I made yet another attempt. Due to impending long days and heavy weeks ahead with my shifts at work, I had placed several of my Petrocosmeas that were showing buds underneath a humidity dome in my basement light stands. In early October, two species were sitting side by side underneath one of those domes, and both were in flower. P. rosettifolia #3 and P. sericea. So, on a whim, I took the pollen from both flowers and made reciprocal crosses between the two species. I then put it out of my mind, assuming, as had always been the case, that both would fail. A month or so later, when I had a chance to check on my plants in between shifts, I noticed seedpods forming on both species!!! WHAT?!! It couldn't be! But, yes, there they were...five seedpods... three on the rosettifolia and two on the sericea! I don't recall how many flowers on each species I had pollinated, but some had indeed worked. Sixty-seven days later, I harvested the seedpods from P. rosettifolia, and then about two weeks after that, the seedpods on P. sericea were harvested. There were seeds inside of all of them.

Eight months after sowing the seeds, the first seedling from the rosettifolia x sericea cross flowered...it was on what had been the most vigourous seedling all along....that plant later was named P. 'Rosemary Platz' after a dear friend. That first year, the plant had five flowers, but the foliage was really nice, and it shaped up very nicely.

Petrocosmea 'Rosemary Platz' in it's third season of bloom...now a mature plant. It has exceeded my hopes and represents three qualities that have now become standards that I select for in all of my Petrocosmea hybrids.....floriferousness, reluctance to form offsets, and attractive, ornamental foliage.

A mature plant of P. 'Rosemary Platz' just coming into flower. This hybrid has attractive foliage, showing the glossiness and lighter yellow veining of it's P. rosettifolia #3 parent. It gets it's leaf shape and size from it's P. sericea parent. An additional plus is that after three seasons of bloom, the original plant has never yet formed a single offset...a trait that I select for in my hybrids. The tendency to offset at flowering ruins many showplants...and is a nasty trait of the P. rosettifolia species used as a parent. P. rosettifolia #3 is the form with yellow veining that is least likely to offset. Form #4 offsets very heavily and is the form of this species that, for me, is the most reluctant to flower. By chance, I used form #3 in this cross.....that was purely an "accident"...but was a happy "accident".

My friend and hybridizing mentor, Dale Martens, took this photograph of a dissected flower of P. 'Rosemary Platz'. This photo shows the attractive purple stigma at the tip of the pistil, and the feathery white furriness of the filaments supporting the anthers.... both traits that neither of this hybrid's parents have. SO where did these traits come from???? ("Thank you" Dale, for allowing me to use your photograph!)

As my third year of Petrocosmea hybridizing comes to a close, I've been very happy with my first hybrid. I've been delighted at the response I've gotten from Petrocosmea growers and gesneriad enthusiasts in general about this hybrid and I hope that it will become a welcomed addition to the world of gesneriad hybrids. This year, I've attempted to take things to the next generation, as I've begun using P. 'Rosemary Platz' and it's siblings, as parents in new crosses. They are now forming seedpods....indications that they may be both pollen and seedpod fertile. I'm excitedly looking forward to the future to see how my "child" behaves as a "parent".

The Winter Solstice

2009-12-21T19:01:00.002-05:00

Today marks the Winter Solstice in the Northern Hemisphere. That means that beginning tomorrow, the days will grow longer. Even though I grow my Petrocosmeas primarily in a basement room with no windows, and the lights are timed the same year round, the plants always have a way of sensing this natural cycle. It always amazes me that they know, but somehow they do.

Some species of Petrocosmea have an annual growth cycle that involves what I have come to term a "semi-dormancy". Right after the autumn and winter flowering period, the plants begin to decline. The outer leaves begin to yellow and will eventually wither. In the center of the plant, the crown of new leaves become thickened and tight...almost as if the plants have an infestation of cyclamen mites. They don't. This cycle repeats every year for some species, and they always burst into rapid, lush growth each spring. The species that exhibit this pattern of growth, for me, are: P. nervosa, P. sp. 'vittatae', P. barbata, P. formosa, P. flaccida, and P. rosettifolia forms #1 and #2. Some hybrids involving these species in their parentage will also show a modified "semi-dormancy". The hybrids exhibiting this modified semi-dormancy are: P. 'Momo', P. 'Asa Blue', P. 'Imperial Butterflies', P. 'Short'nin' Bread', and P. 'Fluffer Nutter'.

One of my two mature plants of P. sp. 'vittatae' after a heavy flowering period. I allow the plant to dry out more between waterings and keep the plant cool. I will groom the dead leaves and flower peduncles off the plant, and will not fertilize it again until I begin to see new growth from the tight silvery center crown of the plant next spring.

The tight, silvery crown of P. sp. 'vittatae' as it retreats into it's annual semi-dormancy. I allow the plant to 'rest' until this center crown begins to expand with lush new growth next spring.

A mature plant of P. barbata 'Keystone'. This plant has been a workhorse of bloom all summer and was the parent of two hybrid crosses when it produced seven full seedpods. It's is deserving of a winter rest. Note how the outer leaves are beginning to yellow. The center crown is taking on the tight, gnarled appearance of it's semi-dormancy. This plant is NOT dying, but resting. Allow it to stay cool, drier, and give it no fertilizer over it's rest. When the new growth begins to emerge next spring, it will make rapid, lush growth. By keeping the roots drier, you avoid rot and root loss. This preserves that large, mature root system, which will support a large, full head of leaves next season. This large rosette of leaves, will nourish a heavy bud and bloom set next season.

The tight, silvery center crown of a P. barbata that is entering it's annual semi-dormancy. The plant is not dying, merely resting.

As the Petrocosmeas wind down from a heavy season of bloom and enter this annual semi-dormancy, it is important to realize that they are not dying. This is a nature response to the changing seasons, shorter days and cooler temperatures of winter. The key to saving these plants is to recognize what is happening and to provide the proper care when this occurs. It is easy to rot the root system if watering is not adjusted. As the plant drops it's leaves, it requires much less water and nutrients to support life. Watering schedules should be adjusted to allow the plants to remain drier, with only enough water to support the very tiny center crown which remains. If done correctly, the mature rootmass will be preserved. This larger mass of roots, next spring, will support a much more lush, and rapid return to full growth. The rosette will be renewed in a shockingly rapid growth spurt. Once growth resumes, I remove any additional offsets or crowns and repot if needed. I DO NOT repot all plants. If a single crown remains and the plant is otherwise happy, I will simply remove the top quarter inch or so of soil and replenish it, add systemic pesticide granules and give the plant a weak fertilizer until new growth is well advanced. Then, I resume my normal care patterns.

Lastly, I will mention that plants grown on reserviors of fertilizer water using the wick watering method, and plants that are kept in a constantly warm environment may not experience this semi-dormancy as markedly as my plants. I attempt to grow my plants as close to what I think their natural habitat provides as possible, so I allow my plants to get quite cool, even cold by some people's standards. I also allow plants to dry out between watering and reduce fertilizers to the point that I am using only plain water for non-blooming plants at this time of year. This is why, I feel, my plants exhibit this pattern.

The Rosettifolia group - Part IV - Still One More!

2009-12-21T18:32:00.002-05:00

In this post of the series on The P. rosettifolia Group from my collection, I will discuss the most reluctant to bloom of the four forms I grow. This form of P. rosettifolia is the one that I label #4 in my collection. It is most similar to form #3 in several ways, but is easily distinguished from form #3 when the two are compared side by side. This form has a tendency to form offsets more than any other form of the species. It's foliage can be the most ornamental, however it's reluctance to bloom and it's tendency to form offsets can make it a challenge to produce a beautiful, blooming plant of this form. In fact, this form never flowered at all for me last year. I had three mature, large plants in my collection and not one flower. They were all grown on the same shelf as the other three forms, all of which flowered heavily. This makes it unlikely that I will use it much in hybridizing. I maintain it in the collection for it's genetic diversity and scientific value.

The flowers of this form of P. rosettifolia have curled petals, deep green "hoods" formed by the upper lip of the corolla and a slight purplish blush to the lower petals.
The flowers of P. rosettifolia #4 have pistils that point upward, due to a curve at the midpoint of the pistil. All other forms of P. rosettifolia present the pistils horizontally and straight.

While the ligthing in this photo is too bright, one can still see the shape of the leaves of P. rosettifolia #4. In this form, the leaves have the attractive yellow central and lateral veining, however, the green is deeper, almost black with good lighting. Leaves are more narrow and the teeth along the margins are present only along the distal half of the leaf. The lower portion of the leaf at the base has smooth margins, without the teeth.

The pistil of the flowers of P. rosettifolia #4 has a curve at the midpoint. This causes the tip of the pistil to be pointed upright, looking almost like the horn of a unicorn emerging from the flowers. The pistil on the other three forms of P. rosettifolia in my collection have straight pistils, which present horizontally from the base of the flower.
The cymes of P. rosettifolia #4 have three bracts, as does form #3. Forms #1 and #2 have only two bracts. The bracts on form #4 are longer and more linear than those of the other three forms.

So there are at least four distinct forms of the species labeled P. rosettifolia in cultivation. I have also seen photos that may indicate there are still other forms of this species out there also. Each species has distinct morphological differences, and DNA testing done on the four forms in my collection does confirm that they are unique individuals within the same species. Judges should keep this in mind when judging this species, as the size and ornamental value of each form can be quite different, as can the propensity towards forming offsets. The amount of bloom for each form can also vary quite a bit.

I will likely be making a couple more posts in this series in the near future. As additional plants that I lump into this group come into flower, I'll review them. The "P. rosettifolia Group", so far, promises to be the largest grouping of individual clones of species and close relatives, that my, with time, be shown to be additional forms or varieties of this species. I place them all within this "group" due to morphological and DNA data. Admittedly, this is a group the I alone, have created, and more learned minds than mine may have different opinions on the subject. Still, other species being grown currently under other names, such as P. sp. 'Chinese #2' , sp. 'China 2005', and the species 'Yumebutai' are the current focus of some study in an attempt to identify proper placement of these individuals within the genus.

Looking Back and Looking Ahead... Hybridizing Petrocosmea

2009-12-09T19:52:00.001-05:00

If you will allow me to deviate from the thread on P. rosettifolia and it's variations, I had to take a few minutes to update you on the seedlings that are flowering now from last year's crosses and the seedpods that are forming on this years new crosses.

With the year 2009 quickly winding down to it's end, I had to take time today to go back and take another long, careful look at the batches of seedlings that are still flowering in the basement plant room. I've spent the entire year nurturing these precious little plants as they went from seedpod to flowering plants. What great fun this journey has been. I've been priveleged to see some seedlings that no one else has seen and evaluated. That's one of the exciting things about hybridizing in general and hybridizing a largely unexplored genus such as Petrocosmea in particular. I've filled my lightstands, my notebooks, my computer (with notes and photographs) and my trashcan as these seedlings matured, some to reveal "keepers" and some to reveal plants that lacked anything new, attractive, novel, or better than the parents. It is a heartbreaking task, to destroy a seedling that is the result of one's own efforts, but it must be done, and I'm proud to say, I've done it. In the end, I've selected some exciting and promising new hybrids for further evaluation.

I'm enjoying the results of two crosses that are now reaching the peak of bloom. The seedlings are the results of crosses between P. sericea x P. minor veined leaf form, and P. forrestii x duclouxii. Both of these crosses have produced variation in both foliage and flowers.

I've snapped some photos this evening of three of the most desireable from the P. sericea x minor seedlings. Foliage on these three is pretty much intermediate between both parents, but the flowers are showing some nice variation in size and coloration.

Three seedlings I'm keeping for further evaluation from a cross between P. sericea x minor veined leaf form. Note in the photo the variations in color of the petals, and the markings in the throat. The seedling in the middle has a clear demarcation between the clear white throat and the medium purple petals. All three flowers have a deep blackish purple dot in the base of the throat. The one on the right is a dark bluish purple, which the camera did not capture accurately. It is darker and more blue than the photo shows. Also note the large leafy bracts on the flower on the right, compared to the tiny bracts on the other two...this is consistent on all peduncles on this seedlings.

This seedling, the one on the right in the first photo, was the only seedling out of twenty to develop large leafy bracts on the peduncle. The hairs on the calyx lobes are also denser and longer than on other seedlings. It's color is the darkest of all of the seedlings in the batch although this photo makes the flower look much lighter in color than it really is.

This seedling has flowers with a clear, clean white throat that is nicely demarcated from the purple in the petals.

The flower on this seedlings is the largest of the batch of seedlings, and consistently has six petals while most of the other seedlings have five. Peduncles are nice and dark in color and are strong enough to support the large flowers. Bud and bloom count was also high for the parentage of the cross. Both parents are not usually heavy bloomers.

The second cross in flower now is P. forrestii x duclouxii. I have selected two seedlings so far, one of which I have named P. 'Keystone's Angora' due to it's soft, silvery furry leaves...the softest of any Petrocosmea that I have in my collection! Of the three seedlings selected, two have been in flower for a couple of months now and are continuing to produce buds...which bodes well for the flower count. The flowers of these two are quite different in size and show a variation in flower shape each taking after a different parent. See the photo below....

Flowers from two selected seedlings from a cross between P. forrestii and P. duclouxii. The flowers are quite different from each other in size. The flower on the left is from an as yet unnamed seedling that is taking it's plant/leaf size and flower shape and size from the P. duclouxii parent. The flower on the right is from a seedling named P. 'Keystone's Angora'. It's flower size and shape is more like it's P. forrestii parent, although both flower size and plant size is larger than P. forrestii. I attempted to pollinate the flower of P. 'Keystone's Angora' with pollen from P. begoniifolia and have several seedpods. You can see inside the throat of the flower in this photo that a small green seedpod is beginning to enlarge....indicating that it may indeed be fertile as a seed parent. Neither flower produces pollen so cannot be used for further breeding as a pollen parent.

While looking back at the past year's successes and failures is fun, rewarding and educational, I am also quite excited to see many seedpods forming on crosses I've made this flowering season. I noted seedpods forming this evening on the following crosses:

P. forrestii x formosa

P. rosettifolia #3 x minor veined leaf form

P. menglianensis x begoniifolia

P. 'Keystone's Angora' x begoniifolia and

P. 'Rosemary Platz' x (Asa Blue x begoniifolia)

I am transplanting small seedlings from crosses of P. forrestii x minor smooth leaf form and P. forrestii x sericea.

With all of these new crosses forming seedpods, and more plants still to bloom, there are still many exciting possibilities still ahead for the year to come. Wish me luck!

The Rosettifolia group - Part III - Yet Another One!

2009-12-09T06:46:00.001-05:00

Certainly my favorite in the "Rosettifolia Group" is this species, P. sp. 'China 2005' The flowers are a lovely purple and the plant is literally loaded with buds and flowers. Easily the most floriferous species of the grouping.

A photo of one of my three plants of P. sp. 'China 2005' just coming into flower this week. This plant is three years old. Maturity of at least three years on Petrocosmea plants is proving to be a factor in heavy bloomset. Most Petrocosmea seen in shows, I suspect, are less mature at one to two years, and therefore often don't show a heavy display of bloom.

Here is yet another plant which I feel based on both morphology and DNA studies,belongs in the the "Rosettifolia Group". It is either another clone of the plants currently labeled P. rosettifolia in the USA, or at the very least, is a close relative or variety of that species. This plant was imported, by myself, as a wild collected plant in the year 2005. In the catalog from which it was purchased, it was labeled P. forrestii... it clearly is not. It shows no similarities with that species. In morphology, it is most similar to the P. rosettifolias, however neither it, nor any of the other plants currently labeled P. rosettifolia match the published description of P. rosettifolia in the Flora of China. AAahh, yes, yet another identification issue with our beloved genus Petrocosmea!

Recent DNA work is showing that P. sp. 'China 2005' is very closely related to the Rosettifolia grouping of species. It may turn out to be another clone of that species, (whatever it is) or at least a variety of that species. The only morphological difference that I can see is that the corolla color is deep purple, whereas the corollas on the other individuals in this grouping are white to very pale lavendar at best. The flower structure and plant structure and habit all match, however. This bloom cycle, I hope to try crossing it with my P. rosettifolias to see if they cross with each other.

The leaves of this species are plain, deep green and have a rough texture due to the short hairs. Leaf size, shape and plant size and habit all very closely resemble P. rosettifolia #1 and #2. This form is a very heavy bloomer...producing waves of buds over a period of four to five months in my conditions. Flowers are a lovely deep purple with a striking, purest white throat, which is slightly green at the very base of the tube. Petals most always number five...two up and three down, with the upper petals fused and bending forward to form a green "hood" as all of the other P. rosettifolias do. The flower morphology places the plant in Section - Anisochilus of the genus.

I have distributed leaves to a number of Petrocosmea growers over the past four years, and hope that this species will get into wider cultivation. It is a lovely plant in flower, and deserves a safe place in cultivation. Since it's place of collection is not known, and with the rate of destruction of habitat in China, it is a constant fear that this species and other plant species will be or may already be lost to nature forever. Keeping them alive in our collections and our hearts and hands is one way to ensure that they continue to amaze and delight us and future generations for years to come.

In bloom, this is one of my most favorite of all Petrocosmeas! Really! The masses of violet purple flowers on wiry peduncles are a lovely, charming gift each December, and they often last four or five months in my basement growing area. No other species has flowers this small and of this shape and color. Most others with this size and shape of flower have pale lavendar or white flowers, so this species is unique in that regard. Out of flower, however, this species is admittedly a bit lackluster in appearance.

Compare the form of this species with that of P. rosettifolia #1 and #2, and perhaps even P. menglianensis in my previous posts. It is hard to tell them apart. The key difference, for me, is that the leaves of this species feel "rough" when compared to those of the other species. Very "sandpaper-like" in texture.

One of the features of this species, which in my opinion detracts, is it's pesky tendency to form offsets when mature. Maturity brings a very heavy budset and flower count, but with the nuisance of offsets which spoil the flat, symmetrical shape of the plant's rosette, which it has to perfection as a younger plant. As can be seen here, even the offset if putting up a few buds.... This little species just loves to bloom!

So, to recap this thread of posts, so far, we have P. menglianensis, P. rosettifolia #1, P. rosettifolia #2, P. rosettifolia #3, and now P. sp. 'China 2005'. There are still others to come! While these plants as labeled, are called by various names at present, they may all turn out to be mislabeled. That is why I refrained from applying a species name to the species covered in today's post, and chose instead to just call it P. sp. 'China 2005'. Such labeling will indicate it's genus, place of origin and the year it was collected.

The Rosettifolia group - Part II

2009-11-28T19:21:00.002-05:00

The next form of "the Rosettifolias" is perhaps the most ornate of them all. The foliage on P. rosettifolia #3 is very showy indeed. It is often a winner at shows when out of bloom due to the light yellow veination along the central and lateral veins of the deep almost black-green leaves.

Petrocosmea rosettifolia #3 is also sometimes labeled P. sp. 'G25KC00'. It was brought into cultivation around the year 2000, after being imported from Chen Yi Nursery (or Kaichen Nursery) in China as a wild collected plant. This form produces the largest rosette of any of the forms. Leaves are more elliptical in shape, forming a sharp point, with teethed or serrate margins. The leaf is very deep glossy green, almost black in the right light. The centers show a bright yellow veination along the central and lateral veins. Leaves are covered in a course hair and have a rough texture. The rosette tends to be very symmetrical naturally. This form does produce offsets quite readily as it approaches flowering, which unfortunately, often ruins the flat rosette. Flowers are produce singly, on stout light green peduncles, with three bracts. Flowers on this form are clear, bright white, with a yellow throat, and often have four or five lower petals.

A flowering plant of P. rosettifolia #3 showing it's white flowers over the striking dark foliage.

The clear white flowers of P. rosettifolia #3 have a lemon yellow center and usually extra petals. Note how the two upper petals are fused into a green hood on the top of the flower. These petals, if measured from base to tip are about one half the length of the lower petals...a characteristic which places this species within Section Anisochilus of the genus Petrocosmea.

My show plant of P. rosettifolia #3 entered in the July 2009 annual convention show of the Gesneriad Society in Silver Spring, MD. The plant won both a first place in it's class and Best Petrocosmea in the show....likely due to the extra ornamental value added by the yellow center veining of the glossy leaves. The contrast is quite showy. The plant was seven inches in diameter.

This photo shows the peduncles on P. rosettifolia #3 which have three bracts, instead of the two bracts found on forms #1 and #2. This form's flowers also have extra lower petals. This photo also shows the rough texture to the glossy leaves and the teeth along the leaf's margins. (The white tag is marking the parentage of a seedpod on the peduncle on the left.) The more compact rosette of P. rosettifolia #2 is in the background. Note that it does not reach the margins of the 5" pot, while the leaves on the larger rosette of #3 are extending over the pot's edge.

A favorite shot of the center of the rosette of P. rosettifolia #3, shows the nice yellow veination forming a yellow feather pattern in the center of the leaves. Even without flowers, this form is a showy plant.

The Rosettifolia group - Part I

2009-11-28T17:10:00.002-05:00

When I first began to assemble a collection of every known Petrocosmea species in cultivation, about five years ago, I noticed that I had two different plant labeled as Petrocosmea rosettifolia. They looked different in several ways. Then as time went on, I began to notice that some of the P. rosettifolias entered in shows were different from the two plants I had. I decided to get leaves of all the various forms I could find and conduct an experiment. I put leaves of all four forms that I had collected down to root on the same day. I treated them identically in every way. When they had formed plantlets, I divided and potted up the plantlets on the same day, using the same soil, pots, fertilizer, etc. I grew them on the same shelf of my lightstand. The culture was identical in every way, at least as much as I could make it so.

As these four individuals matured, I could easily see the differences. I decided to label them P. rosettifolia #1, #2, #3, and #4 so that I could keep them seperately identified and kept records of each form.

Were they different species, or just different clones of the same species, perhaps from different collections or populations in nature? Those questions are still being answered, but with time, based on morphology and now some new DNA analysis, I am convinced that they are indeed four unique individuals within the same species. I do, however, have real doubts that they are indeed the true P. rosettifolia, but I am leaving them labeled as such for the timebeing.

I feel that it is important to both Petrocosmea admirers as well as AV and gesneriad judges and exhibitors to know that there are four different clones of this species in cultivation and they grow and perform differently. Furthermore, I believe that the plants now being grown as P. menglianensis and P. sp. 'China 2005' may also be two additional clones of this same species, based on the DNA analysis which is being done as well as morphological characteristics of these plants. Two others, P. sp. 'Chinese #2' and P. sp. 'Yumebutai' is also very closely related to this group and may be two additional forms of the same species. I refer to all of these collectively as the "Rosettifolia group".

I decided to review the four forms that I have identified here.

The first is of course, P. rosettifolia #1. My plant was labeled as coming from the collection of the late Maryjane Evans, and it is believed to have been a plant collected in China around 1998-2000. This form is the smallest of the four clones in plant size. It has never reached the edges of the 5 inch pan pot in which I have grown it for the past three years. It's rosette is rather tight, and leaves are the smallest of the four clones, and are nearly plain dark green, with only a slight gloss to them. The yellow center vein coloration so prominent in the leaves of some other forms of this species, is very faint in the leaves of this form. Leaf margins are entire, or smooth, showing no teeth as some forms do. The flowers of this form are produced on single-flowered peduncles, with two bracts, which tend to be the shortest peduncles of the four forms and the most often curve gracefully at the tip, causing the open flowers to "nod" downward slightly. The flower form shows two fused upper petals forming an hooded lip, which is green in color and only half the length of the lower three petals, which are a pinkish lavender in color. It forms a rather charming little rosette when in flower. It is a favorite of mine for it's simple charm.

A blooming P. rosettifolia #1, showing it's charming simplistic habit.

The flowers of P. rosettifolia #1 are the closest to pink of any Petrocosmea species in my collection. The subtle coloration of pink, lavender, white, creamy yellow and green is lovely.

The next is P. rosettifolia #2. The origin of this plant is unclear, but it was believed to have been brought into cultivation via a purchase from Chen Yi Nursery, in China. My plant was purchased from a commercial vendor here in the USA four years ago. This plant is very similar to #1, but grows a bit larger in all it's parts. Leaves are larger and the rosette just reaches 5 inches in diameter. Leaves are a bit glossier than #1, and the rosette is slightly more open in form. Flowers are nearly twice the size of the flowers on P. rosettifolia #1. The peduncles are single flowered, with two bracts and are very straight, with little or no curvature at the apex once the flower buds open. Flowers are presented facing outward and upward. Coloration on these is more lavendar, with little to no pink coloration. Flower form is identical to form #1 and very similar to P. menglianensis. This form appears identical in all respects to the plants now being grown here in the USA as P. sp. 'Chinese #2'.

A blooming plant of P. rosettifolia #2. A bit larger than form #1, again without the yellow central veining that some forms show. Leaf margins are entire, showing no teeth. This form bear two bracts on each peduncle.

The flowers of P. rosettifolia #2 are twice the size of those on P. rosettifolia #1.

This photo shows P. rosettifolia #1 on the lower left, with P. rosettifolia #3 above. You can just see the leaves of P. menglianensis to the right of P. rosettifolia #1.. Note the difference in the rosettes of each species, along wit the leaf margins and the yellow veination of the leaves on #3. I believe P. menglianensis to be the same species as the rosettifolias. It's leaves are quite large, and show the yellow veination that form #3 does, but have a smooth or entire margin, whereas form #3 had a serrate leaf margin and a narrower, more pointed leaf shape.

By growing the various forms side by side, it becomes easy to note the similarities and differences in the plants. The photo above shows how they were grown on the lightstand. Note the white acrylic blanket matting in the bottom of the nursery tray, which is used to maintain higher humidity around the plants.

A couple of additional points I'd like to make about the various forms of P. rosettifolia. Forms #1 and #2 have smaller habits, which judges should take into account when judging these species. The leaves are less ornate, having plain green coloration. The leaf margins are smooth, or entire on the forms #1 and #2 and are serrated, with teeth on forms #3 and #4 which will be discussed in the next post. The peduncles of forms #1 and #2 consistently have two bracts, while those of forms #3 and #4 consistently have three bracts per peduncle. Last, I would like to state again, that these plants are labeled P. rosettifolia, but I believe they are NOT the true P. rosettifolia as described in the Flora of China. I believe they may indeed be an undescribed species. DNA evidence being finalized now, shows that the four forms of P. rosettifolia that I am describing here are very closely related, so closely that they are likely all the same species.

Petrocosmea menglianensis - Or NOT?

2009-11-12T09:09:00.001-05:00

I've posted previously about the maddening problem with Petrocosmea species having been introduced under erroneous names. This misidentification or mislabeling, or whatever we choose to call it is a mess now to sort out. I'm excited that there may be some hope towards correcting at least some of the names in the near future.

I've written and spoken for some time now about the particular problem with those plants currently labeled as P. "rosettifolia" and/or P. sp. 'G25KC00'. (Honestly, in my opinion, the label 'G25KC00' is probably the most responsible labeling we could apply to this group of plants right now.) Over time, I have collected at least four different individuals (clones) with these labels. These plants all show similar, but individual characteristics. In my opinion, after growing them all side by side, and conducting a little research of my own, I feel they are all seperate individuals of the same species. Now, I have yet another plant that I would like to add to this grouping - Petrocosmea "menglianensis".

A young, flowering plant that I acquired as P. "menglingensis" (there is no such species with that spelling, I feel it was supposed to have been labeled P. menglianensis (the published spelling of a species). I now feel this plant is NOT P. menglianensis either, but another clone of the grouping currently knows as P. "rosettifolia".

The flower of P. "menglianensis" is almost identical to the flowers of the four individuals that I have acquired as P. "rosettifolia". The flower on this plant is a bit more lavender in color, but morphologically is identical to P. "rosettifolia" flowers.

A side view of a flower of P. menglianensis shows the upper lip, which is the fused upper two petals. The upper lip of the flower is roughly one-half the length of the lower petals, a trait that likely puts this species in Section - Anisochilus of the genus Petrocosmea.

A flowering plant of P. "rosettifolia" #2, the plant is almost identical to the plant labeled P. "menglingensis" when I acquired the former. The plants have near identical flowers and the leaves are identical except that the leaves of the plant labeled P. "menglingensis" are nearly twice the size of the leaves of P. "rosettifolia" #2. I feel they are two seperate clones of the same species.

A flower of P. "rosettifolia" #1, again, nearly identical to the flowers of P. "menglianensis". This form of "rosettifolia" is the smallest of the now five forms of the species that I have. The cymes on this form are darker purple in color, shorter, and tend to curve, causing the flowers to "nod".

I realize this is all very confusing. Here's the breakdown of what I am attempting to say here:

#1 There are at least four different individuals of the same species all labeled as P. "rosettifolia". I feel that this new plant, which I acquired as P. "menglingensis" is yet another form of the same species.

#2 All four (now five) plants in this grouping all likely NOT the true P. rosettifolia. None of them match the published description of that species in the Flora of China.

#3 The plant which is the subject of this post originally came to me, and is still being sold and distributed as P. "menglingensis"...which is an erroneous spelling of P. menglianensis (the published species name). I feel that this plant is NOT P. menglianensis, and is yet another different clone of the plants all now being grown as P. rosettifolia. It is NOT P. rosettifolia either, but is almost identical to all of the other plants being grown under the erroneous labeling of P. rosettifolia.

#4 If my hunch is true, there are now at least five different individual clones of this same species, which is not yet properly identified.

#5 If you have this plant, I would recommend continuing to keep it labeled as it is, in order to identify it seperately from the other "P. rosettifolia" clones....BUT with the knowledge that it is likely not either P. menglianensis OR P. rosettifolia....we simply don't have a proper identification on any of these plants at present.

WHEW!!! I hope this is all as clear as mud, at least. Either way, the plant is still lovely, and a welcome addition to the genus in my plantroom. It does grow much larger than any of the other forms of the species (whatever species that is?) and should be grown in for no other reason than to preserve it's genetics. The leaves on this form get quite large on a mature plant and with maturity, in it's third of fourth year, it can bloom quite heavily.

Petrocosmea 'Keystone's Harvest Moon' - A Petrocosmea For Autumn

2009-11-11T11:21:00.003-05:00

Sometimes, one of the toughest things about hybridizing gesneriads is selecting a name for the hybrids. (the second toughest thing is the selection process where most of the seedlings to flower must be thrown into the garbage bin!) I was surprised a couple of years ago, while looking at a batch of hybrid Petrocosmea seedlings to note that one of them had leaves that were yellow...definately more yellow or golden than all of it's siblings. My first thought was that the plant was just chlorotic, so I repotted it and gave it a heatlthy dose of fertilizer. It only became more yellow! As the plant matured, I had removed some of the leaves to test whether the propagations from the leaf cutting would show the same trait. They do!

This seedling was eventually selected due to the unique trait of the golden yellow overlay of color on the leaves. I noted that various exposures to light produced slightly different degrees of intensity in the yellow coloration, but this plant always remained more yellow than all the other Pets. I suspect that it's parent, P. rosettifolia #3 which was used due to it's deep yellow veining in the leaves is the contributor to this trait. The flowers, being light lavendar, make a lovely color contrast to the yellow foliage.

So, what to name it? The yellow color appears to be overlaid upon the green leaves underneath, like the glow of a full moon upon an object, so I was inspired to name the plant 'Keystone's Harvest Moon'. The cross is P. rosettifolia #3 x sericea.

A young blooming plant of P. 'Keystone's Harvest Moon'. While the flowers are produced on long pedicels, a trait I normally wound have culled out in a seedling, the yellow pigmentation of the leaves promises the beginning of some interesting foliar characteristics if I can get the plant to hybridize. One of my goals for hybridizing Petrocosmea is to introduce new, more ornamental foliage, since often Pets are entered in shows as "non-flowering" entries.

A close up shot showing the lavendar flowers of P. 'Keystone's Harvest Moon'. This color makes a lovely contrast with the yellow foliage which can be seen in the background.

A photo showing P. 'Keystone's Harvest Moon' on the right, beside a young plant of P. menglienensis, to show the yellow foliage color of 'Keystone's Harvest Moon'. The plant is NOT chlorotic. I have tested it with a number of leaf propagated plants and all show the yellow leaf color even in various conditions. Light intensity tends to affect the degree of yellow coloration, with higher light producing the most intense yellow coloring.

The Three Petrocosmea minors - Part 3

2009-11-05T19:19:00.004-05:00

A flowering plant of Petrocosmea minor veined leaf form. This form grows larger than any of the other forms, with heavier substance. Leaves and even flower petals show deeply incised veining along the central veins, lateral veins and even in between the lateral veins.

A close up photo the foliage of P. minor veined leaf form. Very glossy and bubbly in appearance, making quite an attractive plant in or out of flower. This form also seems to propagate the most quickly and readily from leaf cuttings and has the fastest growth rate of all the forms.

A close-up shot of the flower of P. minor veined leaf form, shows the recurved petals with the deep veining of the lower petals. Cymes are single to multiple flowered, with more branching of cymes on more mature plants. Cymes of this form have a sturydy, heavy substance.

The third form of P. minor in cultivation is the form now called P. minor veined leaf form. This form has been distributed as P. sp. '#5', P. sp. 'Chinese #5', and simply P. minor. It differs from the other forms most obviously in the deep veining of the large, heavy, glossy orbicular leaves. The petiole often has dense, quite long silvery hairs covering it, with these hairs being golden amber to brown near the base of the petiole. This form did succeed in a cross with P. sericea, using sericea as the pod parent. Seedlings of the cross can be seen in an earlier post on here a few days ago. The leaves of the seedlings do show the influence of P. minor veined leaf form, as they are all deeply veined even as small plants.

As new Petrocosmea species are collected and brought into cultivation, additional forms of P. minor are showing up. The plant pictured above was just collected and imported from China in late 2008 and appears to be another clone of, or at least very closely related to P. minor. I have small seedlings of this new form in my collection and am anxiously awaiting first flowers.

I hope that this discussion of the various forms of Petrocosmea minor is informative and helpful to enthusiasts and judges. Further study of these plants are causing me to be more and more certain that all of these plants are NOT truly P. minor. They differ from the published description in many significant ways. I feel more and more that these represent an undescribed species or "new" species to cultivation. Until this is confirmed, however, I recommend that plants be grown and labeled as we describe them here. Retaining the source of your plants is important. I try to keep records of the original labeling and source of all of my Petrocosmeas in the hopes that soon a taxonomist will provide come clarity to the labeling of these spectacular gesneriads.

The Three Petrocosmea minors - Part 2

2009-11-02T07:03:00.002-05:00

A flowering plant of Petrocosmea minor pointed leaf form shows the smaller flowers, branched cymes or peduncles and smaller rosette size. Note the tips of the leaves on the leaves in the middle of the rosette have a pointed tip due to the margin of the leaf "rolling under" on each side. Once the leaves age, this tends to flatten out and the leaves take on a more rounded or orbicular shape.

The second form of P. minor to show up in cultivation in the US was the form now called "pointed leaf form". This name refers to a characteristic of the younger leaves to roll under at the margins near the apex of the leaf, causing a point to form at the tip. This form is often still exhibited as P. minor without any designation of the variety or form. This form differs from the smooth leaf form in several ways. The rosette tends to stay more compact or smaller in size. The growth rate is slower, for me. The color of the leaves is deeper green and the veining is slightly more prominently incised or "deeper" than with the smooth leaf form. Leaves are not as glossy as on the other two forms. Flowers are smaller, more cupped and have a large white throat. They are bluer in color than the more purple or violet color of the smooth leaf form. Petals are smooth with slight veining, although not as deeply veined as seen in the flowers of the veined leaf form. Lastly, the inflorescences, or peduncles are branched, with primary and secondary bracts. Calyx lobes are longer, there are still six of them, however, being longer, they form a "bell" around the bud, which in this form, tends to hang downward or droop on the inflorescence until just prior to opening.

Judges should note which form they are judging as the different characteristics might be viewed as culture flaws by the inexperienced judge. The pointed leaf form is the smallest of the three forms, is significantly slower to mature for me, and is not as glossy and shiny as the smooth leaf and veined leaf form. Also, in this form, the leaves do not lay as flat on the rosette, causing a more open and upright form to the rosette. These points could easily be attributed to poor or inconsistent culture resulting in a "stressed" plant by a judge, and therefore marked down in the scoring.

A flower of P. minor pointed leaf form.....note that it is smaller, and more cupped, with the calyx extending farther onto the upper lip. The white throat is more pronounced.

A cyme or peduncle from P. minor pointed leaf form. Not that there are primary bracts at the base of the first two branches and secondary bracts at the base of each calyx. The buds hang downward and the calyx lobes are longer forming a cup around the buds. Cymes are rarely ever single flowered, most always they are branched with three to five buds being typical.

Note the secondary bracts at the base of the calyx. This is the only form of P. minor to have this trait.

A close up of the center leaves of the rosette of P. minor pointed leaf form. In the early stages, leaves are more cordate in shape, with a pointed apex, but as they mature, they become more circular or orbicular in shape near the outer rows of the rosette. Leaves show deeply incised veins along the midvein and the lateral veins only.

The Three Petrocosmea minors - Part 1

2009-11-01T18:00:00.001-05:00

A flowering plant of Petrocosmea minor smooth leaf form.

Since first coming into cultivation around 1999, the plant labeled P. minor has been a favorite among Pet admirers. The plant appears to have come into cultivation in the US via an independent vendor from China who sold that plant labeled as P. minor. Almost from the very beginning of it's cultivation, though, the plant's identity as P. minor has been in question. To add to the confusion, in the next few years, new forms of the species began to show up in shows. The plants were very similar in many respects, but had distinct differences in both leaf form, growth habit and flowers. I decided to do a series of posts on the forms of this species that I have in cultivation in my collection.

The flower of the plant I grow as P. minor smooth leaf form. The flowers are borne on single flowered cymes...rarely two-flowered.

Lets begin at the beginning. Initially, there was just the one form of P. minor..the one pictured above, in the US. At the time it was introduced, it was called simply, P. minor, as it came labeled from the vendor. The plants were reported to have been collected in China. Leaves on this form were round...orbicular is shape with smooth dorsal (adaxial) leaf surfaces. The plant habit was flat, symmetrical, and the leaves were distinctly glossy in appearance. Flowers are grape-purple, with a white throat and a deep violet purple almost black spot at the very base of the throat, deep inside the corolla. Cymes or peduncles were single flowered, rarely two-flowered. Cymes have three bracts consistently and calyx lobes are six in number..which is odd for a Petrocosmea where all species except P. kerrii have five calyx lobes. (P. kerrii has three calyx lobes).

The three forms of P. minor...smooth leaf form on the top, veined leaf form on the lower left and pointed leaf form on the lower right. All three of these plants are the same age, in a five inch pan pot, and were grown side by side under the same conditions for one year previous to the photo being taken. P. minor smooth leaf form is intermediate between the two in size of the rosette and has the smallest and glossiest leaves. Veining on the leaves of smooth leaf form is very shallow. Leaves cupped in a convex manner.

A cyme and flower bud of P. minor smooth leaf form, showing the six lobed calyx, with the upper three lobes being shorter than the lower three lobes. Cymes are usually single flowered.

Soon after P. minor was introduced, two other forms became evident. One of these, the form now called P. minor veined leaf form, was originally labeled P. sp. '#5' or 'Chinese #5'. I have grown leaves of this form from various sources, all labeled as #5 and Chinese #5 and have found them all identical to P. minor veined leaf form. The veined leaf form is the largest of the three forms in all respects. The leaves are much heavier in substance, with very deep veining along the dorsal (adaxial) surface, giving it a pebbled appearance to the leaves. It's flowers and cymes are also different from the smooth leaf form. The third form is now called pointed leaf form and I have also seen it labeled P. minor holly leaved form. This form has the smallest rosette of the three forms. It grows much more slowly than the other two forms and has branched cymes with smaller flowers. The leaves on this form fold under at the tip and along the margin to give it a pointed appearance. When the leaves of this form are flattened, however, they are also rounded or orbicular in shape. This form has leaves that are a deeper green color than the other two forms and the leaves are not as glossy, although the dorsal (adaxial) surface remains glabrous or smooth (free of hairs).

Flower cymes of the three forms of P. minor....from left to right...smooth leaf form (left), pointed leaf form (center) and veined leaf form (right). The smooth leaf form consistently has three bracts on the cyme, whereas the pointed leaf form also has secondary bracts and a consistently branched cyme.

The flower structure of the P. minors appears to place them within Section -Anisochilus within the genus Petrocosmea. This section has flowers which have shorter upper lobes...roughly one half the length of the lower petal lobes, and the upper lobes fuse to form a hood or upper lip that has two lobes. This characteristic is also present in the flowers of P. sericea and the P. rosettifolia group.

Culture of the three forms of P. minor is consistent with the culture of all other Pets. Since these are some of the largest of all Pet species, they will need larger diameter pots as they mature. I keep them in five inch diameter x two inch deep pan pots (shallow pots) at maturity, although they would easily grow into larger pots if given them. I find these species quite slow to mature, compared to many other species. I allow them to dry out between waterings. They tolerater drying out better than other species, perhaps because the leaves are of a heavy substance and succulent. In hybridization attempts, I found all of the P. minors to be very difficult to work with. They did not accept pollen from each other, by selfing or from other species. They did cooperate as pollen parents in two hybrids, with P. sericea and P. forrestii.

The last thing to note about these species is that all three forms appear to NOT match the description of P. minor in the Flora of China. Differences in the leaf shape (being round or orbicular in shape), size and texture (being glabrous or smooth on the dorsal leaf surface) as well as the six lobed calyx, and the shape of the filaments, cause them not to match any currently described species description within the Flora of China in my opinion. I have studied the flowers, cymes, and leaves under a microscope and carefully compared them to the description within the Flora of China and cannot find a match among the twenty-plus descriptions of Petrocosmea species contained therein.

So, even though these beautiful Petrocosmea species are currently suffering a bit from an identity crisis, they remain among the most unique and beautiful Pets in my collection.

Stay tuned for Part 2 and Part 3 of this series on P. minor!!!

Petrocosmea minor Hybrids - First Flowers

2009-11-01T11:23:00.000-05:00

It is always a happy day when a new Petrocosmea seedling flowers for the first time. Usually by that time, I have been able to study to foliar characteristics from the seedlings, but the flowers often show surprisingly high variation in color and characteristics. The latest cross to flower is P. sericea x minor veined leaf form. This is one of only two crosses I was able to get using P. minor and both crosses produced few seeds. In this cross, two plants with similar floral structure were used, and the closer relationship to each other within the genus may have been why this cross succeeded when others have not. Both P. sericea and P. minor exhibit flower structure that appears to place them in Section - Anisochilus, where the upper two petals are often reduced to one half the length of the lower three petals. The two upper petals are fused together into an upper lip or hood with two lobes. This flower form is also seen with the various forms of P. rosettifolia, P. sp. 'China-2005' and P.
cavaleriei and P. sp. 'HT-2' and P. sp. 'Yumebutai'.

The seedlings all show very uniform foliar characteristics, appearing much like a hairy leaf form of P. minor veined leaf. The cupping of the leaves, seen in P. sericea is only showing up in one seedling, so far. The flowers of the two seedlings which have flowered so far, show some variation between the two parents, with one flower looking more like P. sericea in color and form, showing no white in the throat. The second seedling looks more like the P. minor parent, and showing the white throat of this parent. Both seedlings show the promise of becoming quite large plants, and I will be potting them on into larger pans soon to allow them to develope more.

One characteristic that I am not liking in these seedlings is that they both have very long, wiry peduncles. I'll evaluate that in the next flowering with more maturity. If the plants do indeed grow into large rosettes, the longer peduncles may be necessary for the flowers to extend beyond the long petioles of the leaves in the rosette, so I am not too concerned yet. They peduncles do both show a nice wine-purple coloring.

The first seedling to flower from the cross of P. sericea x minor veined leaf form resembles P. sericea in flower form and color.

The second seedling to flower resembles P. minor veined leaf in flower form and color.

All of the seedlings have been quite uniform in foliage form, looking like a fuzzy leafed form of P. minor veined leaf form as can be seen in this seedling above.

The flower of Petrocosmea sericea - very similar in form to P. minor flowers. The two species are likely very closely related to each other. The two upper petals are fused into a two-lobed lip or "hood" to the flowers. Upper petal length is roughly one half the length of the lower three petals, and likely places these species in Section - Anisochilus, along with the plants labeled P. rosettifolia, whose flowers are very similar in shape.

The flower of Petrocosmea minor veined leaf form also share the flower form and structure of Section- Anisochilus with P. sericea..the other parent in this cross. In this form of P. minor, the leaves are deeply veined. This form also shows the veining in the lower petals of the flowers, which the other forms of P. minor do not have. The flowers of this form are a bit smaller and have a more pronounced clear white throat.

A Weekend With Petrocosmea

2009-10-26T17:30:00.001-04:00

Autumn is my favorite season. Here in the northeast, it can be a spectacularly beautiful time as the trees and shrubs outdoors begin to show vivid colors. The blue sky outside my front door is framed with the most brilliant golden yellow leaves of the maples in all directions. While cooler weather and fall color marks the end of the growing season for the gardens outside, for Pet lovers, it marks the beginning of the heaviest period of bloom for many of the species. This autumn has been a beautiful one and a busy one, so far.

The photo above is a scene from Lewiston, NY, on Goat Island at Niagara Falls. This past weekend, I was priveleged to spend an entire weekend studying Petrocosmea genetics! (with a brief side trip to "the Falls". ) I must keep you in suspence a bit longer, but we are getting some interesting data on the interspecific relationships of the Petrocosmea species we have in cultivation at this time. This information will hopefully contribute some valuable data to our knowledge of this fascinating genus that is still largely unstudied. Of course, the taxonomic component still needs a lot of work, and we are slowly but surely working on that too.

Having access to a microscope allowed me to spend some time studying the anatomical and structural characteristics of Pet species. I could spend months just looking down those lens and gazing at the minute, and miraculous features of each species. Above are some quick, ten-minute sketches I drew of the anthers and filaments of P. nervosa and P. minor-smooth leaf form. The pollen is stored within two "pillow-like" cavities on either side of the mid-line of each anther. The pollen "shoots" out of an opening at the tip (pointed area) when pressure is applied to the "pillow". The shape of the anthers is one of the features that determines species' placement within the three Sections of the genus Petrocosmea. The more rounded shape of the tip of the anther of P. nervosa place it in the most primitive section..Section : Petrocosmea. The pointed tip of the anther of P. minor "likely" places it in Section : Anisochilus (that is my guess). The filaments of P. minor were thick and globular, with a white apex and deep blackish purple violet base. The tiny hairs on the filament were white, with purple tips on the white apex.....the pigments in the filament looked like little purple jewels under the microscope. Amazing and very beautiful!!!

As you can see from the drawing above, two things are evident. First, I am NOT an artist!! and second, there is much to learn from the differences in the anatomical structures of Petrocosmea. I hope to spend much more time in the next few months attempting to iron some of the mysteries and frustrations with the mis-labeling of species and perhaps even confirm that we have some unidentified (undescribed) species within our collections! For me, sketching and drawing the floral parts allows me to focus on every minuted detail. It is a trick I learned as a nursing student many years ago. As I draw, I notice things that I had never noticed before. Try it with your own Pets when they flower. Remove a leaf or a peduncle and spend a few minuted dissecting the structures and studying them. You'll gain a renewed appreciation for the miracles of nature and Petrocosmea!

Excitement continues in the plant room with all of the seedlings coming into first flower. The latest seedling to flower from the cross P. 'Asa Blue' x begoniifolia. Again, something new! This flower has some reddish and pinkish pigment. Note the reddish pigment in the upper petals near the base and at the base of the throat. (The picture doesn't do it justice!). This flower is quite large...the largest so far, and the petals are very broad and rounded with an unusual "serration" along the margin (I have no idea where that came from??!!) A different shape than any of the Pets we have so far. While the plant is still tiny, it is putting out a great number of buds.

The new seedling, (left) with a sibling (right...the more typical shape so far), to show the different shape of the new flower. The flower is large, and the peduncle is nice and short, and strong. This one has a lighter pinkish color also, sort of mauve in color. It definately deserves to be kept for further evaluation. Foliage has a nice purple band around the edge...as can be seen in this photo.

Photo of P. nervosa in flower. I love this species. The blue flowers floating above the silvery leaves.

One last comment that I keep getting lots of questions via email about. Shallow pots. Let me just say, if you are struggling with growing Petrocosmea....my first bit of advice is always... "Shallow pots, shallow pots, shallow pots!!!". Once after giving a talk where I had just advocated and preached the virtues of using shallow pots for Petrocosmea culture, a lady came up and proudly announced that she NEVER used shallow pots and her Petrocosmeas won awards all the time in standard pots. She was quite proud of herself and her Petrocosmeas and wanted to let me know that I was mistaken. It was a fun conversation and I got a chuckle out of it. YES, Petrocosmea can be grown very well in standard pots. I'm sure prize-winning specimens could be grown in pots three feet deep if one wanted to adjust culture to accomodate this. But, in my experience, shallow pots prevent a lot of extra effort and disappointment from root rot when the large volume of soil results in soil staying damp for too long. Shallow pots, allow more air to get to the roots, more horizontal room for the shallow and wide root system to roam and great evaporative surface area to increase humidity, keep roots cool, and again, allow soil to dry quickly after watering. They just work better for me. I've used them in the humid and hot south of the USA, the mountains of West Virginia, and now the cooler climate here in Pennsylvania. I use them in windowsill culture and under lights, with top watering, bottom watering, mat watering and wick watering, all with better results than I get from a taller, deeper, narrower standard pot. And, the plants seem to shape up better, with nicer symmetry with the wider diameter of the shallow pots or "pans" as they are usually called. But, to answer the question I keep getting, YES, Pets can be grown quite successfully in standard pots as long as one is cautious of the potential for root rot. As for me, I'll use shallow pots.

Tribute to a Lovely Lady - P. 'Rosemary Platz'

2009-10-18T15:56:00.003-04:00

The flower of Petrocosmea 'Rosemary Platz', my first hybrid. The flower shows the influence of both parents. A lovely sky blue from P. sericea, with the yellow in throat from P. rosettifolia #3.

Friends are among the dearest of all things in our lives. My love of gesneriads has afforded me the opportunity to meet so many wonderful people who share my fondness for these plants and I now count many of those people among my best friends. When my first hybrid Petrocosmea flowered a couple of years ago, I knew exactly who I wanted to honor with the naming of the first selection. Rosemary Platz is one of those spirited, energetic people who makes anyone she meets feel good. Her smile is bright and constant, and her laughter is infectious. A beautiful person, inside and out, she always wants to learn more about gesneriads, and she is an accomplished grower, a master judge, and skilled designer in gesneriad shows. I am honored to call her my friend.

My dear friend, Rosemary, at the annual convention of the Gesneriad Society last July.

P. rosettifolia #3 was the seed parent from my hybrid. This form has the eye-catching yellow patterning along the central veins of the dark green glossy leaves. Seedpods took 67 days to ripen. The cross produced pods with large quantities of seeds and excellent germination.

The pollen parent, P. sericea. This species contributed the pleasing lavendar coloration to the flower, as well as it's size and form. A reciprocal cross using P. sericea as the pod parent produced few seeds, from which only two plants have survived.

My original plant of P. 'Rosemary Platz' is now coming into flower for it's third bloom cycle. Each time it flowers, I am reminded of my friend, and it's namesake. (As it comes into flower, I will post a photo of the whole plant, showing the foliage.) It has proven, so far, to be an easy plant to grow. It shapes well for show, and has so far, had no problems with disease or insects. Leaves are glossy and show the best qualities of both parents. In a five inch pot, my plant is maintaining a diameter of about six inches and it has more flowers each time it blooms, as it gains more maturity. It propogates easily from leaves and the plantlets grow quickly and flower at an early age, usually about five or six months. I've been pleased with it. The name was registered with the Gesneriad Society last January. It marks the first time either species has been used in hybridization.

In Bloom Today...The "White" Petrocosmeas

2009-10-18T14:46:00.002-04:00

The clean, white flowers of Petrocosmea begoniifolia at are a lovely contrast to the dark green, purple-backed leaves that this plant bears. The purple of the leaves is carried into the pedicel and calyx, as can be seen here. The flower also has two lemon yellow splashes and has a more cup shaped corolla than most Pet species.

Although white flowers in the genus Petrocosmea are among the minority, it occured to me this morning as I tended my beloved Pets that all of my white-flowered species are in flower now. I've always been partial to white flowers, any white flower...gardenias, magnolias, white roses....and the white flowered Pets are also among my favorites. So, I thought I would take advantage of natures gifts to post an entry about the white flowered Pets I grow.

Petrocosmea kerrii boasts white flowers with yellow highlights, much like P. begoniifolia, however, the yellow highlights on P. kerrii are uniquely on the top petals or "roof" of the throat, rather than the "floor" of the throat. Now, I have to see if I can cross P. kerrii with begoniifolia and get flowers with yellow on both the top and bottom petals??!!!

It was interesting to me, to note that ALL white-flowered species have yellow in the flowers....something that is rarely ever noted in the blue flowered species. The yellow is usually found on the lower petals....with the exception of P. kerrii. P. kerrii is placed within Section Dienanthera of the genus, where a yellow blotch on the upper petals is a characteristic of the species within this section. (P. formosa, which has lavendar flowers is also placed within the Section, and it too, has yellow on the upper petals. ) By crossing the white-flowered species (with yellow in the lower petals) and the blue-flowered species (with no yellow in the flower), I have been able to get some yellow in purple flowers on the hybrids.

The Petrocosmea rosettifolia group (I have at least four different forms of P.rosettifolia), generally has lavendar flowers, with the exception of one form which I received labeled P. sp. 'G25KC00'. I have since labeled it P. rosettifolia #3. This form is the only one with white flowers. I used this form in my first hybrid - P. rosettifolia x sericea and got one white flowered seedling which also happened to be a miniature sized plant. I named that hybrid P. 'Keystone's Bantam'. All of the other seedlings from that cross have been lavendar, so far, however, I have about twenty more to flower this year, so I may still get some new white forms.

The white-flowered form of P. rosettifolia which I labeled #3 in my collection in order to identify it seperately from the other three forms that I have. This form also has three bracts on the cyme, and the flowers have a heavier substance and larger size than the other forms of the species that I grow. The cymes are also larger in diameter and grow taller.

The dainty little charmer, P. barbata has flowers that almost always open white and stay white until the wither. For others, these same plants produce lavendar flowers, so P. barbata may not truly be "white flowered", and the trait may be cultural or environmental. It has the smallest and most fragile, thin flowers of any of the Pet species, for me. A heavy bloomer that is often among the very first species to bloom as Pet season approaches each autumn. One other thing of interest with this species is the fact that it tends to have a "semi-dormancy" after flowering where the outer leaves are dropped and only a tightly cupped center "button" of green leaves remains, until spring approaches, when the plant once again, springs into growth.

Petrocosmea 'Keystone's Bantam'--- My only white-flowered seedling from among about forty seedlings that I have flowered, so far. The happy result from my first hybrid cross P. rosettifolia #3 x sericea. This seedling was tiny from the very beginning and has never exceeded three inches in diameter, even after three years of growth on the original plant. Flowers are large for the size of the plant, and are purest white, with NO yellow! The flowers on this seedling resemble the flowers of the rosettifolia parent, pictured above, most closely, while the flowers on all of it's siblings have favored the sericea parent more. The little plant originally had an "odd" center that resembled a little furry button, (note this in the photo above), however, the plant grew out of this and now this same plant has a "normal" center of tiny leaves. The plant above is in a two inch pot. Potting it into a larger pot did not result in a larger plant. Leaves are a little more reluctanct to produce babies than it's siblings, however, the plant does propagate true from leaves. It is quite floriferous at maturity and has been used once successfully in a hybrid with P. forrestii, which has produced 100% seedlings that are just as small or smaller than P. 'Keystone's Bantam'. I am awaiting the first flowering of these seedlings this winter. This is, I believe, the first and only hybrid Petrocosmea to date with white flowers.

So, now that I am blessed with an assortment of white flowered Pets all flowering at the same time, you KNOW that I have to attempt some hybrids among them. P. kerrii might introduce more flowers into hybrids, since it's flowers are often borne in clusters of several flowers each. P. kerrii also has the potential to extend the yellow to the upper petals of the flowers, so in combination with another species with the yellow in the base of the flower, one might acheive flowers with yellow on all petals. P. rosettifolia #3 has a lovely yellow veining down the center of the dark leaves, so more attractive foliage might be possible with it as a parent. So, the potential is certainly there for some exciting new hybrids! Now, off I got to the plant room...........

Barney, The Cat

2009-10-17T13:45:00.001-04:00

I've had a few inquiries and requests for a photo of Barney, The Cat. Here he is! My profile description mentions that I am the personal assistant to Barney, which is true. Barney took me on as his "P. A." about twelve years ago, when he was leaving the home of my sister upon the impending birth of my nephew, Matt. Barney was not willing to share a home with a newborn infant, so was actively seeking new accomodations at the time. Finding himself in search of a new residence and "P.A", Barney offered me the position after he had conducted a thorough inspection of my residence. He informed me that my employment was on a trial basis and that I would be offered permanent employment only upon having met his strict standards and requirements. I was reluctantly offered the job.

As can be clearly seen by Barney's expression in the photo, he merely tolerates my presence, and often finds me a nuisance. I am occasionally allowed on the sofa and the bed which he uses daily. When I am allowed to sit on the sofa with him or sleep on the bed with him, I am allowed only along the edge, since he requires the middle of the bed for himself.

Barney observes a strict diet, which he demands to be served, often at three a.m. He drinks only the highest quality and purest of water from an immaculately clean dish. My failure to observe his strict and demanding dietary requirements results in a vocal protest that will not cease until his requirements are met. This vocal display is accompanied by a forceful thrashing of this tail.

Barney, too, is a plant enthusiast, and often enjoys strolling about the plant room and sunroom as I tend the plants. He also enjoys horticultural journals, and will eagerly position himself squarely in the middle of whatever page I am attempting to read in the journal at the time.

Posted by Tim, Personal Assistant to H.R.H. Barney, The Cat.

Petrocosmea cavaleriei - A New Kid in Town

2009-10-17T13:16:00.002-04:00

The flower of P. cavaleriei. Very similar in appearance to P. sericea and P. sp. 'HT-2'.

By now, those who have been reading my blog have probably realized how much I love to announce a new addition to my collection of Petrocosmea, and when the new addition is a species, I am on Cloud 9. Recently, I've been enjoying and studying the blooms on P. cavaleriei, which my friend Mike Wenzel of the Atlanta Botanic Garden was kind enough to share with me last year. The label on the leaves I received show it having been collected in 2005, but gives no further information.

This photo shows one of my plants, growing in a four ounce condiment cup, with a diameter of about four inches. The plant is very similar in appearance both in leaf and flower, to P. sericea and P. sp. 'HT-2'. The plant, in all parts, though, is smaller than either of these species, and the leaves have a slightly different shape. Flowers are very similar in appearance to these two species also, with the exception of a much hairier calyx.

The Flora of China description, appears to match my plant pretty closely. FOC lists P. cavaleriei as having been described by H. Leveille in 1911 from material collected in Guizhou, China.

It is always exciting anytime a new species comes into cultivation. I have already distributed a few leaves and plants to friends, in the hope that this beautiful new addition to our Petrocosmea collections will become more widely cultivated and appreaciated. I feel we all have a responsibility to try our best to preserve plant species whenever we can. Often Petrocosmea are found in very limited numbers in a few or perhaps even one lone site on a hilltop or valley that is vulnerable to development or other loss of habitat. As was done with me in this case, the passing along of leavews or cuttings from friend to friend is how many of these rare beauties are distributed. I have acquired perhaps 85% of my Petrocosmea collection via this method. So, share your Petrocosmeas with a friend, you might just be helping to save a precious species from extinction.

A New Seedling Flowers!

2009-10-10T20:07:00.000-04:00

P. forrestii's flower is nothing special as far as striking features, but it makes up for the lack of drama by the shear numbers of flowers produced! It was easily the most prolific parent in my hybridizing efforts last year. It rarely failed to produce seed when pollinated by another species.

The flowers of P. duclouxii are among the largest of the Petrcosmea species. The shape is unique as is the deep purple blotch at the base of the throat...something no other species has. (This species is almost certainly NOT the true P. duclouxii..... I feel it matches the description of P. grandiflora more closely.)

The first flower from a cross of P. forrestii and P. duclouxii. A much reduced version of P. duclouxii on spectacularly soft foliage!

Having made 14 new Petrocosmea crosses last year, I am excited to see the cooler months of autumn approaching, for that means the peak season of bloom for my Petrocosmea collection is here! And this year, with the bloom season comes the special bonus of seeing many of those seedlings begin to flower for the first time. This week, I am excitedly watching buds develop on a batch of seedlings resulting from a cross between P. forrestii and P. duclouxii. The first to open is pictured above.

The seedlings resulting from the pairing of the floriferous and compact little species P. forrestii and the large, and equally floriferous P. duclouxii have been my favorites, hands down, in the foliage category. I love the foliage on these little guys! The leaves on these seedlings look like large P. forrestii leaves, but are incredibly furry....the hairs on the leaves are dense, long, and very soft. I have always believed the plants should be experienced with all of the senses, including the sense of touch. One of the endearing charms of many Petrocosmeas is the way the foliage feels when it is touched. These seedlings have among the softest, if not the softest foliage of any in my collection. P. duclouxii has long, soft hairs on the dorsal of the leaves, so I was happy to see that they inherited this feature.

Now as for the flowers, I honestly was not expecting anything spectacular here, since I fing the flowers of both parent species to be nothing special. I made the cross with a goal of a heavily flowered, very symmetrical plant, that did not sucker and was easy to grow. I can't say that I have acheived any of those qualities with just a lone flower on one of twenty seedlings, but there are lots of buds coming, so I am still hopeful of floriferous plants. The flower, as you can see above, is a smaller version of the flower on P. duclouxii. I see no sign of P. forrestii in the flower, other than the flowers' reduced size and less prominent purple blotch at the throat (which P. duclouxii is noted for.).

One last note to make....... As I am seeing more and more flowers opening on Petrocosmea hybrid seedlings, I am noting a curious, and disturbing trend.... Many of the flowers have malformed, or missing anthers. Some, as with the seedling above, also have missing or deformed pistils also. If this continues, it may result in Petrocosmea hybrids that cannot be used for further hybridizing. I'm continuing to watch this. This is also noted in some Sinningias...especially the doubles; in Kohleria hybrids, and in some Chirita hybrids.

The journey continues!!!!

Propagation of Pets - Producing Seeds

2009-10-02T09:38:00.001-04:00

Seedpods forming on Petrocosmea forresttii at about 6 weeks after pollination.

Propagation of Petrocosmeas from seeds is unfortunately a rare occurence for most of us. For years, the only option many of us had to grow Pets from seeds was from the small quantities of seed that the late Gesneriad Society Seedfund Chairperson, Maryjane Evans produced. Maryjane was able to produce seeds from gesneriad species when most other people failed. She managed to produce seeds from a few species in the late 1990's and those quickly disappeared from the seedfund list. But, recently I've had some success. I thought I would share what has worked for me, in the hope that others might be able to produce Petrocosmea seeds.

For me, the two key factors that have proven necessary through three flowering seasons now are 1) high humidity, and 2) low temperatures for both seed production and seed sowing. In my conditions, I have been unable to produce any seeds in the absence of either of these factors. When both are present, I get seeds 33% of the time. While not great percentages, it is sufficient to get more seeds than I can grow.

So here's how I do it and what I've learned. First, as the plants start to show buds forming underneath the leaves, I place the entire plant inside a plastic nursery tray that is lined with a section of acrylic blanket cut to fit the tray. This blanket is kept barely moist until I harvest the seed pods. I place a plastic humidity dome over the tray so that the plant is enclosed in a "terrarium" environment. The tray is placed on the light shelves where the Pets normally grow and the plant's care remains the same as always. As the flowers open, I wait until they are open about four or five days. At that time, I note that the stigma has enlarges a bit and if viewed under a magnifying glass, it appears "sticky". At this point it is receptive to fertilization. I remove the pollen from the "father flower" and place as much of the pollen as I can onto the stigma. I label the flower with a small tag containing a number, which I note in my hybrid log with the cross and the date. If fertilization occurs, the stigma will "reorient" itself and will point upwards at approximately a 45 degree angle. The ovary will begin to enlarge. I sometimes remove other flowers and buds on this plant to allow more energy to be focused into the seedpod's formation.

Petrocosmea seeds. This photo was taken by my friend Dale Martens. She photographed a packet of seeds that I had shared with her.

Once the seedpods begin to enlarge, I start to count the days. For me, Petrocosmea seedpods have ripened between 57 and 80 days, depending upon the species used as the pod parent. I harvest the seeds, label them and place most of them into the freezer, inside a double layer of ziplock bags to ensure that no moisture gets to them. In this way, I've had good germination on seeds stored for one year. I only plant a small quantity of the seeds for both insurance in case the first planting does not germinate, and because I do not have the space to grow hundreds of seedlings from each cross. I have now accumulated quite a "bank" of Pet hybrid seeds in my freezer!

Petrocosmea seedlings two weeks after germination. I plant on either straight fine vermiculite or peat pellets that I moisten and sterilize in my microwave for three minutes on high.

I've now sown more than 50 batches of Petrocosmea seeds. I've had some total failures and some thrilling successes. I've learned a couple of critical points. First, the seeds must be sown on sterile medium. I microwave whatever medium I use in the microwave on the high setting for three minutes. I allow it to cool and sow the seeds. I sow the seeds in an enclosed environment, such as a ziplock bag or covered plastic bowl as shown above. The seeds must not dry out. Perhaps the most critical factor, though, seems to be cool temperatures for seedling germination. This has been proven now by myself and four other growers. Petrocosmea seed germination seems to be greatly enhanced by keeping them quite cool...for me around 40 degrees F seems to work best. Warm temperatures in the 60 degree or higher range has resulted in total failure to germinate for me in three seperate experiments and has had the same results for four other growers now. I have no idea why this is a factor for both seed production and germination. Perhaps in nature, the seeds are produced in the winter and early spring months so that the resulting seedlings will have a longer time to produce good root systems before the following winter hits them??? I don't know, but I do know that for me, cool temps are crucial in my environment.

The happy result of persistence in attempts to produce seeds on Petrocosmeas. These are the seedling community pots from three of my current crosses.....where am I going to find the room to grow all of these seedlings???? (Note the tray in front shows the seedlings from a cross I made with the intent of producing miniature Pets....these seedlings are the same age as the seedlings in the other two pots!)

A nursery tray underneath the lights in my basement. These are seedlings from the same cross of P. 'Asa Blue' x begoniifolia. Note the variation in the foliage texture, color and shape.

Once the Petrocosmea seeds germinate, I move them to slightly warmer temperatures to increase the rate of growth. After about a month of age, I begin to fertilize the seedlings as I do my mature Pets. Seedlings usually flower for me in about 8-9 months from seed sowing.

I am often asked if Pets are known to be self-fertile and do the self-pollinate. I have never had a Pet self-pollinate. If I get a seedpod, it is always the result of my crossing activities. So, if the ovary begins to enlarge, I usually always have a successful pollination. Since my success rate is only about 33%, I try to pollinate several flowers. That usually gives me one or two seedpods from each cross. Some pods produce one or two seeds, some hundreds. I've only had an empty seedpod once, on a cross that I attempted to make on a plant that was not in a terrarium. It was the only plant to ever form pods outside of an enclosed environment, but when I opened it, it was empty.

Lastly, I have found that some species seem to be happier to become parents than others. For me, P. forrestii has been a prolific seedpod parent, but has failed as a pollen parent. P. rosettifolia #3 is the same. P. duclouxi, P.barbata 'Keystone' and P. nervosa are also great seedpod parents. P. sericea is a fair parent as either the pollen or seedpod parent. P. minor does not want to cross with any of the other Pets. It has been reluctanct, having only been a pollen parent in two crosses.

So, do try to make some Petrocosmea crosses. I tried every year for ten years before I stumbled upon my current methods. It was just an accident that it worked, but I am most grateful that it did work!!!

Environment and The Delight of Petrocosmea Hybridizing

2009-09-23T15:44:00.002-04:00

A trio of flowers of siblings from a cross of P. 'Asa Blue' x begoniifolia. L to R are P. 'Keystone's Barnswallow', P. 'Keystone's Bluebird', and P. Keystone's Whipporwill'. This cross has had amazing variation among the flowers and leaf types produced.

When I saw the first seedpods developing on P. rosettifolia three years ago, I was ecstatic! I litterally skipped around like a little girl who's just been given a new pony! Ten years of attempting to get a Petrocosmea flower to produce seeds had finally paid off....now, the question was...."What did I do differently?" Why had it happened this time and not any of the hundred attempts before? Being schooled as a nurse in a nursing program where the model taught me to consider the environmental factors and stressors as factors that impact outcomes, I decided to take a moment and study what factors in the plant's environment were different this time and how were they different. Without boring you with all the details, when I studied this, I came up with two key differences this time....humidity and temperature. After testing those factors for anther year, and documenting my variables and factors...I am convinced that these two factors must be just right for both successful pollination and germination of the seeds to occur.

The first flower to open in the P. 'Asa Blue' x begoniifolia cross. This flower is quite large, with yellow, purple, and white in the flower. Petals are six in number, with slight ruffling, and white fantasy splashes in the flowers. I want to test this plant and future bloom cycles to make sure these qualities are stable before naming and releasing it, but WOW, what a flower!

Humidity is a major factor in successful pollination. I've now tested this several times and have found that unless the flowers being pollinated are grown in very high humidity, such as is found in an enclosed or terrarium-like environment, successful fertilization is rare, and seed production if pods developed, is zero percent! Only once have I gotten seedpods on flowers outside of an enclosed environment, and that time, all three pods were totally empty of seeds. This was also the only time I've gotten a "false" pregnancy with empty seedpods. Inside an enclosure, I am getting approximately 33% success.

Petrocosmea 'Rosemary Platz', my first named Pet hybrid, named for a beautiful lady and a dear friend of mine. The result of that first cross, which was P. rosettifollia x sericea. You can see that the yellow central veining in the leaves of P. rosettifolia was passed along to this hybrid. Flowers look like huge lavendar P. rosettifolia flowers. The plant got it's leaf size and shape and flower color, from P. sericea.

P. 'Keystone's Bantam',(rosettifolia x sericea) named for my friend Paul Kroll's prized bantam chickens, is the sibling of P. 'Rosemary Platz' shown above. This plant is tiny...never exceeding three inches in diameter. From the point that it germinated, this seedling was always very tiny and a bit of a slow grower. Leaves are deep green with yellow veining like P. rosettifolia, and the flowers are very large for the plant size and pure white with light green throats. The little plant blooms very heavily, although it is a strong seasonal bloomer for me. I selected it for it's miniature size and beautiful white flowers. I have used it in one cross with P. forrestii in the hopes of producing miniature Pet hybrids... SO far, the seedlings are all even tinier than 'Keystone's Bantam'.

P. 'Keystone's Harvest Moon' (rosettifolia x sericea), another remarkable seedling resulting from the first cross. These leaves are not chlorotic...This plant shows an incredible yellow blushing over the entire leaf surface in good light. The yellow veining is also present in the leaves, but the entire center of the leaf is yellow with a dark green margin. LOVELY! Flowers are lavendar and look great above the yellow foliage. It is now in bud and I hope to post some photos of the entire plant in bloom soon.

The second factor that seems to play a major role in successful fertilization is temperature...cool temperatures. Although temperature is slightly less a factor, I do believe it plays a role in both fertilization and germination of Pet seeds. My successful crosses have only occured with room temperatures of 45 degrees F or less. Above that, and I have less success, even with flowers that were grown in enclosed environments. In warmer temperatures, fertilization did not occur. As the temperatures dropped, I once again began having success. With regard to germination of seeds, this has been reproduced by several growers and myself now several times. In warm temperatures, germination was poor or failed to occur. When I placed the seed containers in cooler rooms, germination improved significantly and was even "heavy". Experienced growers of gesneriads from seeds have had the same results when I've shared Pet seeds with them.

I continue to study these factors on a daily basis with my Petrocosmea hybridizing program. I attempt to study the effect of temperature and humidity seperately and together. If you have Pets in flower, you must try to make some crosses. It is great fun and there is so much to be learned about this genus and it's culture. Keep notes of everything you do and the factors observed when you do it. Reviewing those notes in the future will likely be amazingingly instructional.

I'll post more on the factors involved in hybridizing Pets in future posts. Stay tuned!

Petrocosmea 'Keystone's Barnswallow' - Introducing a New Petrocosmea Hybrid!

2009-09-23T13:25:00.003-04:00

Petrocosmea 'Keystone's Barnswallow' - the flowers are deep blue/purple with a white halo effect at the base of the upper two petals and two yellow lines in the throat.

Having an opportunity to introduce one's own hybrids is always great fun. I'm excited to be able to introduce a new Petrocosmea hybrid - Petrocosmea 'Keystone's Barnswallow', the happy result of a cross utilizing the new Japanese hybrid 'Asa Blue' as the seed parent and the species P. begoniifolia as the pollen parent. From the very beginning this has been an exciting hybrid cross!

The cross was exciting for a number of reasons. First, it was a Petrocosmea cross, that alone is exciting, since there have been so few! Hybridizing Petrocosmeas, while I've been fortunate to have some success, has not been easy. Sixty seven percent of the time, I fail to produce seeds when I attempt a Pet cross. Secondly, though, this cross in particular was a breakthrough because it utilized a Pet hybrid as a parent. I believe it may be the first successful Pet hybrid utilizing a hybrid as a parent, ever! The few that have been made, so far, have always been primary crosses between two species. This cross proved that at least some Petrocosmea hybrids are fertile. It is only the second cross, that I am aware of, that utilized P. begoniifolia as a parent. I was interested in using this species because it has white flowers, it has yellow in the flower, and it has purple pigmentation in the leaves and pedicels and peduncles as well as the the calyx lobes. I felt that introducing purple pigmentation into the plant's various parts would be an exciting characteristic of hybrids. So, there were lots of high hopes for this cross...and it has exceeded my hopes!

The cross produced two full seedpods and lots of seed. I had good germination, and from the early stages, I could see a good deal of variation in the leaves on the baby plants. The cross has P. begoniifolia, nervosa, and flaccida in it's background, and among the 30 seedlings that I am growing out, I can see plants with dominant features of each of the three species in the foliar characteristics. I was very happy to see that many of the plant began to bloom at an early age, and for young plants, are still producing lots of buds and flowers. This definitely comes from the 'Asa Blue' parent, which blooms heavily, over a long period, and blooms as a quite young plant. The plants are taking on a very pleasing leaf symmetry and shape from a very early age.

A photo of the whole plant. This photo shows P. 'Keystone's Barnswallow' in a three inch pan pot. Foliage is showing a bit of chlorosis in the photo due to the plant being placed on shelf with new T-8 lights and getting a bit more light than it likes, however prior to this, the plant had lovely deep green, glossy foliage with the nice pebbling effect that begoniifolia has. Flowers are a pleasing contrast of deep blue against the green foliage. There are still lots of flower buds underneath those leaves!

A photo of P. 'Asa Blue', the seed parent of my cross. P. 'Asa Blue' is a remake of the cross that produced P. 'Momo' the first Pet hybrid. The cross is P. flaccida x nervosa. 'Asa Blue' produces flowers of a medium to light lavendar, while 'Keystone's Barnswallow' has much darker blue/purple flowers that hold the deep color until they fade.

The pollen parent for 'Keystone's Barnswallow' ...the lovely species P. begoniifolia. I chose it in the hybridizing effort because of the flower shape, it's white color, with yellow in the throat, and the purple pigment in the calyx lobes and pedicels as can be seen in this photo.

The cross has produced a lot of good flowers, but several have been discarded as "nothing new". I have selected five so far to keep and evaluate further. P. 'Keystone's Barnswallow' is surely the best so far. Across all of my hybridizing efforts, I am selecting seedlings for two qualities in general.... 1) early, and prolific flowering across a long period, 2) attractive, ornamental foliage that shapes well and does not tend to offset easily. With individual crosses, I may have other goals. This new hybrid I feel, meets both goals. 'Keystone's Barnswallow' began flowering in early June and has been in continuous flower ever since. It has at least 15 more buds that I can count underneath the foliage. And, while several of it's siblings have formed offsets, it has not and shows no sign of doing so at this point.

The Parryorum's are in bloom.....

2009-09-20T05:11:00.003-04:00

Single flower of Petrocosmea parryorum.

For me, the blooming of Petrocosmea parryorum is a thrilling event. Well, for me, the blooming of any Petrocosmea is a thrilling event, however, this one is a particularly special event. P. parryorum has always been a tough species to flower in my conditions. I've never figured out why. Others bloom it easily, but that is certainly not the case for most of us. So, last week, when those first few flowers started to open, I began to check my plant several times a day, in anticipation of it's coming into full flower. The time has arrived!

When researching P. parryorum, one of the first things I noted was that it was not listed in the Flora of China....then it hit me. P. parryorum is not FROM China, so that is probably why. P. parryorum was found in India and Burma by Cecil Ernest Claude Fischer (usually written C.E.C. Fisch.) in 1926. I have been unable to find much more than that on either the plant or the man Mr. Fischer. The plant, was not listed by Craib in his first revision of the genus done in 1919, because it was not known then either. So, one is left with the scant information in Wang's Second revision of the genus done in 1926, where it is called the "Indo-Burma Petrocosmea". It is placed by Wang in Section Anisochilus, noted for the top two petals of the corolla being approximately one half the length of the lower lip of the corolla...which they are.

Scant information, however, does not diminish the beauty of the plant in my eyes. It is a favorite plant for me. This species is often maligned by judges when it is entered in the "not in flower" classes for being "just a plain green plant". I would argue that it is green and it is a plant, but it is far from plain if one takes the time to know it. All parts of the plant are densely covered in long silvery hairs that give the plant a "frosted" or silvery appearance in the correct light. These hairs are often more golden in color near the base of the plant of the base of the petiole. The leaf surface is pebbly and the leaf is heart-shaped. If given proper culture and good light, the plant can be quite attractive. But the event of it's flowering is wonderful. Tight clusters of buds emerge from the crown of the plant to unfold into silvery furry clusters of lavendar flowers. The color of the flowers against the silvery hairs is lovely indeed, a feast for these Petrocosmea enthusiast's eyes!

A cluster of P. parryorum flowers emerging from the silvery, hairy crown of the plant....

This photo, by Julie Mavity-Hudson, shows the many attributes of P. parryorum...the glossy sheen of the pebbly leaf surface. The silvery hairs grab the light to give the plant a "frosted" appearance.

So, how did I get it to bloom? P. parryorum has been in my collection for about ten years...maybe more. It has only bloomed twice...last year with one spike of five flowers and this year, when it has more than a dozen inflorescences with multiple buds on each. I am not sure what I did differently. I grew the plant enclosed under humidity domes, for the past two years...which I have never done before. Also, I used to repot Pets about twice a year. And I never let the plant get very large before I would restart it as a leaf cutting and grow a new plant. I was in my African violet period then and thought that frequent repotting was the way to go....for Petrocosmeas, I am now convinced it IS NOT the way to go. My Petrocosmeas that I have allowed to remain in the same pot for four or five years now definitely perform best. I am now convinced that allowing Pets to mature is a secret to success. My plant is in a 5 inch pan pot where it has remained for four years now. It is quite rootbound. I remove the top of the soil about twice a year and place fresh soil with systemic pesticide granules mixed in. This is the only pest control that I use and I have never seen any insects on my plants. It grow it in the basement of my home, where temperatures the past two winters have gotten down to 38 degrees F. The Petrocosmeas loved it. I keep many of them enclosed under humidity domes and the ambient humidity in the room is usually greater than 50%. I allow P. parryorum to dry out at the root a bit between waterings. I use a variety of liquid fertilizers and alternate them at random. I fertilize about twice a month. Light on the shelf where P. parryorum grows is quite dim by most light gardener's standards. The plant sits below two tubes of light at a distance of about 16" from the leaf surface to the light fixture.

I had hoped to take photos of the mature plant in flower, however I dropped the plant while cleaning the shelves and broke off many of the leaves. That was not a good day to say the least, but the plant seems to have suffered no ill effects other than being mis-shapen and bruised. I am already attempting to make crosses using P. parryorum.

So if you haven't tried P. parryorum, you must! But be patient. It is worth the persistence and the wait.

Petrocosmea nervosa and sp. 'vittatae' - Are they the same species?

2009-09-15T14:58:00.004-04:00

Petrocosmea sp. 'vittatae', sometime distributed as P. vittatae, is obviously a close relative, if not the same species as P. nervosa. P. vittatae is not a valid species name.

I have always had a special fondness for Petrocomea nervosa. It was one of the earliest Pets that I learned to grow and it never fails to bloom faithfully and heavily for me every year. The grey, silvery hairy foliage crowned with a mass of blue flowers never fails to make me feel happy when I look at it. My three plants of P. nervosa are all putting on their best show for me right now.

One of my happy P. nervosa plants in bloom today. Notice the offsets near the center crown.

Petrocosmea nervosa flower.

The upper petals being nearly the same length as the three lower petals is one of the characteristics that places P. nervosa within Section Petrocosmea of the genus Petrocosmea. This section is believed by some taxonomists to contain the most primitive species within the genus based on flower structure and the configuration of the anthers. As morphologically similar plant labeled P. vittatae was introduced into cultivation a few years ago. The late Maryjane Evans spent much effort researching the origins of the new plant material as well as the name P. vittatae and found nothing. The person who gave the plant to her could not recall from whom they had originally gotten the plant, and the species P. vittatae is not a valid published species within the genus. I have noted that P. sp. 'vittatae' grows larger and has leaves of heavier substance, and substantially larger in size than P. nervosa, when grown side by side with uniform culture. Both plants offset heavily as they approach maturity and tend to only flower once they have produced offsets. The flowers of both plants are identical in every way for me in my conditions and the plants bloom at the same time. If shown a leaf, though, I can usually tell which leaf is 'vittatae' and which is nervosa, due to the larger size and thicker, heavier substance. I find that sp. 'vittatae' matures a little faster than nervosa in my conditions and tends to produce plantlets from leaf cuttings faster than nervosa.

P. sp. 'vittatae' on the left and P. nervosa on the right. Both of these plants were grown side by side in the same tray on my light stands and were taken from leaf cuttings put down to root on the same day. They are shown in five inch pan pots.

P. sp. 'vittatae' growing on my lightstand. From this photo, one can see that I grow this species with quite dim artificial light. Note the offsets...this species and P. nervosa bloom for me only once they have produced offsets.

I grow both species in quite dim light. SHALLOW pots...a must!, an I keep soil evenly moist with occasional short periods where I allow it to dry a bit. I find that these species are a bit more succulent than some others and prefer soil a bit drier. Once potted in a five inch pan pot, I leave them there for several years as long as they are happy and healthy. I find that they bloom most heavily when not disturbed and allowed to mature and get a bit rootbound. I remove a thin layer of soil once a year and replace it with fresh medium containing systemic pestacide granules. I have never been troubled with insects with this treatment and my plants seem happy.

SO, what do you do if you have P. vittatae? First, keep it if you like it. A few years ago, once it was announced that research had found no such species as P. vittatae, some experienced Pet purists were saying that any plant labeled "P. vittatae" should be thrown away and NOT distributed as there was "no P. vittatae". My feeling is that it IS a Petrocosmea, and it IS a slightly different plant than P. nervosa...so we should continue to grow it and keep the plant labeled as something new and different. I changed my labeling from P. vittatae to P. species 'vittatae'...in order to designate that it is a species that is unidentified and was given a cultivar name of 'vittatae'. Whether that is right or wrong, it allows me to keep it seperately labeled in my collection and it continues to adorn my home and enrich my life with it's beauty....regardless of it's name. You know....."A rose by any other name.........."

Petrocosmea xingyiensis - A New Species Described!

2009-09-15T14:11:00.002-04:00

Thanks to my friend Jaco Truter for informing me of the publication of a newly described Petrocosmea species from China -- Petrocosmea xingyiensis! Published in the June 18, 2009 edition of Novon, the species is described by Yi-Gang Wei and Fang Wen. You may find the description here: hua.huh.harvard.edu/china/novon/novo-19-02-261.pdf

The authors place this new species in Section Anisochilus ser. Iodioides. The plant was collected near Ghizhou Province, in the Maling Gorge, Xingyi County, Southwestern China on 7 Oct. 1998 from cliffs of limestone rock or along the Qingshuihe River at 930-1000 meters elevation. The population was believed to be less than 330 individuals in the habitat and is listed on China's Red List of endangered species. An article I read on this area states that the State is building a dam which is expected to flood the Gorge and destroy much of the habitat. It is indeed sad to think that this lovely new species could be lost to us if it is not already. We may be about to lose this species just as we are learning of it's existence.

An Overview of Petrocosmea - To Know Them Is To Love Them

2009-09-13T19:31:00.002-04:00

One of my favorite Chinese proverbs states that when someone shares something of value with us, we have an obligation to pass it on to someone else. I think that sums up my reason for starting this blog....

When my interest in knowing more about Petrocosmea first began, I found it extremely difficult to find information about the genus, and even more difficult to find information on proper culture of the plants. It is my hope, that in writing about what I have learned, and continue to learn about the genus as I continue to study it, that others who want to know more and grow Petrocosmea more successfully will find the information helpful.

So, I thought with this post, I would review the genus as a whole.

The genus Petrocosmea was first described in 1887 from Dr. Augustin Henry's Ichang collections by Daniel Oliver when he described the species P. sinensis from western Hubei, which is a province in central China, near the Yangtze River. In 1919, William Craib wrote the First Revision of the Genus Petrocosmea. No further revisions were done until Wang Wencai did the Second Revision in 1985. The genus includes three sections: Section Petrocosmea, Section Anisochilus, and Section Dienanthera. Among the three sections, the total described species in the 1985 revision is 27 known species and 4 varieties. A 28th species...P. formosa, was described by B.L. Burtt in 1998. The name Petrocosmea comes from the Greek words for "pretty" and "rock". The chromosome count for Petrocosmea is 34.

The geographical distribution of the 28 species contained in the genus includes 24 species and 4 varieties from Western and Central China, with the remainder found in Myanmar (Burma), Thailand, NE India and S. Vietnam. The species are often found in very restricted locations, in forests, growing among limestone rocks at elevations from 300 - 3200 meters. This elevation is typically cool to rather cold in temperature. Humidity is generally high due to mists at these elevations, and the locations are often near streams. The species are often found on only one or two mountain tops or on one or two islands.

The center of the rosette of P. sericea. I really like the cupping of the leaves on this furry species! It is one of the slowest growers of the genus, at least in my conditions.

The first Section described was Section Petrocosmea, which includes the species considered to be the most primitive of the genus. This section of genus contains seven species and one variety. One of the distinguishing features of the species in this section is that the upper lip of the corolla is nearly equal to the lower lip of the corolla. It contains the species P. flaccida, P. nervosa, and P. grandiflora. Examine the flowers of these species, and it will be apparent that the upper petals and the lower petals are very nearly the same length.

The flower of P. duclouxii, which I suspect may actually be P. grandiflora. This plant has also been distributed as P. floribunda, a species name that is invalid.

The second Section described is Section Anisochilus, the largest section, containing 16 species and two varieties. P. parryorum is a commonly grown species found within this section. One distinguishing feature of the species within this section is that the corolla upper lip is half the length of the lower lip. This section also includes P. barbata, P. rosettifolia, and P. forrestii

The flower of P. rosettifolia #1.

The foliage of P. rosettifolia #3. The lovely yellow veining along the central and lateral veins is passed along in hybridizing to the progeny....something I was happy to discover!

The third section within the genus is the last to be described, being added by Wang during his revision of the genus in 1985..Section Dienanthera. The flowers of this section have a uniquely different pollination mechanism from the other two sections. The anthers are constricted below the apex to form a short "beak" that actually ejects the pollen from the tip of the beak when pressure is applied to the base of the beak. P. formosa is a species found within this section along with P. kerrii. The species within this section often have a rather large leaf blades with longer peduncles.

So, as your Pets come into flower this season. Take the time to examine the individual flowers up close. I have learned a lot about the genus by examining the flowers. I am often asked if I know the natural pollinators of Petrocosmea. I do not. I have been unable to find any information or even speculation on how the flowers are pollinated in nature. If anyone know, please let me know!