Cited by Liede & Meve, Novon 11: 173 (2001). Also a type of Cynanchum rusby Malme. Nom. nov. based on Vincetoxicum umbellatum Rusby, non Cynanchum umbellatum Vell. Cited by Liede & Meve, Novon 11: 173 (2001). Also a type of Vincetoxicum umbellatum Rusby.