National Council for The Conservation of Plants and Gardens
National Collection of the Genus Codonopsis and Allied Genera
A large, vigorous twining climber not often seen and seed lists usually prove to be Cc rotundifolia var. angustifolia or pilosula. This is surprising since C.tangshen is the only member of the genus, at least as far as we are aware, with an inferior calyx i.e. the calyx lobes completely enclose the calyx when the flower opens. The large flowers are greenish throughout sometimes with internal markings and the seeds are large and brown. C.tangshen will hybridise with others and we have grown a rather attractive hybrid in the past but, sadly, not photographed and now lost.
Since writing this it has become clear that we have never grown a pure specimen and are greatly indebted to the previous collection holder, Paul Kneebone, for the loan of his photos of the true Codonopsis tangshen showing quite clearly the inferior calyx.
China and much used in Chinese medicine