Numerical Taxonomy of the Asclepiadaceae s.l.

Abstract

A SET of 58 characters was recorded comparatively for a sample of 76 species belonging to 31genera of the Asclepiadaceae R.Br. The characters cover variation among the species in gross vegetative morphology, floral features and structure of the pollination apparatus. The data-matrix was analyzed using a combination of the Jaccard measure of dissimilarity and Ward’s method of clustering in the PC-ORD version 5. Two major groups are recognized in this treatment, the first comprises representative genera of the Asclepiadoideae, while the second is split into two subordinate groups corresponding to the Periplocoideae and the Secamonoideae. Tacazzia seems better removed from the Periplocoideae and placed in the Asclepiadoideae. The generic concept in the family is taxonomically sound; only representative species of Cynanchum were divided between two closely related low-level groups. The currently accepted tribes and subtribes in Schumann’s classification are in need of thorough revision; only the Secamonoideae-Secamoneae emerged intact.