A mysteryious plant – Ceropegia radicans ssp. smithii
It was always an irrevocably fact to me that this form is nothing but an naturally occuring hybrid of Ceropegia radicans and Ceropegia sandersonii, as both species are well known to hybridize readily with each other in cultivation – and in fact there are several such forms to be found under a clutter of names.
It was ….
There are many botanists who accept this plant as a subspecies (or variety) of Ceropegia radicans.
According to the original description the two subspecies of Ceropegia radicans are neither geographically nor ecologically isolated, that means, both occur in the same region, and even share the same habitat (the valley of the Kwelega River in the East London District of South Africa’s Eastern Cape Province).
They are said to differ from each other by the shape of the flower, whose lobes form a cage-like (in the ssp. smithii) resp. a narrowly pyramidal structure (in the ssp. radicans).
In the year 1911, P. Roth reported in “Die Gartenwelt” the first (documented) artificially produced hybrid of two Ceropegia species.:
“Eine künstliche Kreuzung, C. sandersonii, befruchtet mit Pollen von C. radicans, hatte jedoch Erfolg. Dies ist die erste erfolgreiche beabsichtigte Kreuzung bei Ceropegien.”
“An artificial crossing, C. sandersonii, pollinated with pollen of C. radicans, yet was successful. This is the first successful intended crossing among Ceropegias.”
There are many such hybrids to be found in the trade today, some go by names like “Apollo”, “Jupiter” or “Mars”, and they mostly are very similar to Ceropegia sandersonii, or even much more so to the plant that we now want to call Ceropegia radicans ssp. smithii, respectively.
Whatever now the truth may be – the plant shown on the photograph goes back to material that was collected (around 1985) in the wild!
– Dr. P. Roth: Über Ceropegien. Die Gartenwelt 15(25): 337-339. 1911
– O. A. Leistner: Flora of Southern Africa. Vol. 27(4); Botanical Research Institute, Dept. of Agricultural Technical Services 1980
The photograph shows a plant that can be traced back to collections made by P. V. Bruyns himself – this is its ‘field number’: PVB 2162, Blue Water Police Station, Kwelegha River, E. London, RSA.
Photo: by courtesy of Friedericke Hübner & Ulrich Tränkle