Aspidonepsis, an endemic southern African genus, is described and compared to the closely allied genus Aspidoglossum. This newly described genus is composed of two subgenera, Aspidonepsis and Unguilobium, consisting of three and two species respectively. Asclepias diploglossa, A. flava, A. cognata and A. reneensis are transferred to Aspidonepsis, and A. shebae is newly described. All species are discussed, illustrated and a key is given to aid in their identification.