Cynanchum

Cynanchum, a genus of Asclepiadaceæ, of which some species have been used medicinally—e.g. C. monspeliacum as a violent purgative, the so-called Montpellier Scammony, and C. vincetoricum, formerly in repute as an antidote to other poisons. The Indian C. extensum yields fibre, and C. ovalifolium of Penang, caoutchouc.