Wednesday, September 2, 2009

Petrocosmea flaccida - A New Clone !

Petrocosmea flaccida 'ABG 1990-1581' - a dainty new addition to cultivation!

I was pleased during a visit to the Atlanta Botanic Garden in June, 2005, to find that they had in cultivation a new collection of P. flaccida. As I've said before, new Petrocosmeas always create a stir, so I'm sure my excitement was evident to my friend Mike Wenzel, who was patiently showing me around. At the conclusion of my visit, he was gracious enough to offer me a couple of leaves. Now, I treasure it in my collection.

As for the history lesson, ......Petrocosmea flaccida is often one of the first Pets that many of us started out with. It's name refers to the flaccidity of the soft, silvery leaves. P. flaccida was first described by Craib in 1919, having been collected in Muli, Southwestern Sichuan, and near Yongning, in northwestern Yunnan Provinces in China. Plants were found "growing on rocks in thickets, 1830-3,000 meters above sea level." It is grouped within Section: Petrocosmea of the genus, which as of the second revision of the genus done by Wang in 1985, included only 4 species and one variety. P. nervosa, another of the older Pets in cultivation, is also contained within Section : Petrocosmea.

The "traditional form" of Petrocosmea flaccida, which I have grown for a number of years. This plant is growing in a four inch pan pot and is approximately six inches in diameter.
My "traditional" P. flaccida, which I've spent many years with now, grows significantly larger than this new form. The leaves on my P. flaccida are more cordate in shape, and are nearly three times as large in diameter as the dainty little leaves on the new one. The flowers are darker on my older form, larger, and have two prominent white dots at the base of the lower petals on either side of the opening of the throat. The new form does not have these dots.

The new P. flaccida 'ABG 1990-1581' is much smaller in all regards. Leaves have a rounder shape, and are only about one third the diameter of the regular P. flaccida's leaves. This plant is in a three ounce condiment cup and the whole plant is less than four inches in diameter. I tiny little plant....

A photo showing both forms of P. flaccida in my collection. These plants were grown side by side on my light shelves and had uniform culture. Both plants are in their second year of growth and second flowering season.

A well grown P. flaccida exhibited in the Gesneriad Society Convention in Silver Spring, MD this past July.
Having a new collection of P. flaccida is exciting for several reasons. First, it is great to have now genes available, as most P. flaccidas are likely just propagations from a few original plants. The new form also offers an exciting option for hybridizers (like me). One of my goals in hybridizing Petrocosmea is to create miniature Petrocosmea. I have a couple of promising tiny Pets and this new P. flaccida, with it's small stature, will definately be involved in some hybridizing efforts this year! As for growth and culture, it definately needs a smaller pot. Placing this plant in a four or five inch pot would likely result in the loss of the plant due to root rot, and would be of no benefit as I doubt it would ever need such a large pot. Otherwise, I grow it exactly as I do my other Pets. I have noticed that it is painfully slow to propagate, but if one is patient, it is easy to prop. It is just going to take a while for it to reach a decent size.
I began distributing leaves and plants this year at the Gesneriad Society convention, so hopefully, within a few years, this new form of our old friend will make it's way into more homes!