The canopy-effect of the united corolla-lobes is not always obvious and the deciduous nature of the leaves is variable too, but the distribution of the species which covers a wide area in the Transvaal, seems to justify its specific status. The small apical canopy of the corolla has some similarity to the larger canopy of C. rendallii, which is to be found in the same area as C. decidua and further afield. This leads to speculation that C. rendallii may have played a part in the evolution of C. decidua, although the characĂ‚Âteristic falcate inner corona-lobes of C. rendallii are not reflected in the latter.
