DIOSCOREACEAE

the yam family of the flowering plant order Liliales, consisting of 6 genera with more than 500 species of herbaceous or woody vines and shrubs, distributed throughout tropical and warm temperate regions. Members of the family have thick, sometimes woody roots or tuber-like underground stems and net-veined, often heart-shaped leaves that sometimes are lobed. The small green or white flowers of most species are borne in clusters in the leaf axils. The fruit is a winged capsule or a berry. Several species of yams (vines of the genus Dioscorea) are grown for their edible tuberous roots, such as Chinese yam, or cinnamon vine (D. batatas); air potato (D. bulbifera); and yampee, or cush-cush (D. trifida). A few species are cultivated as ornamentals. Black bryony (Tamus communis) is a European perennial vine with yellow flowers, poisonous red berries, and poisonous blackish root tubers. Dioscorea is a principal raw material used in the manufacture of birth-control pills.