Monday, December 21, 2009

The Rosettifolia group - Part IV - Still One More!

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.