New combinations and new names in Malagasy Asclepiadoideae (Apocynaceae)

In the genus Pentatropis, P. madagascariensis is recognized as a subspecies of P. nivalis. In the stem-succulent species of Cynanchum, is considered a northern subspecies of C. gerrardii. All species of Folotsia, Karimbolea and Platykeleba, as well as the Malagasy species of Sarcostemma, are formally transferred to Cynanchum.