The flowers are generally small and individually inconspicuous, though collectively showy. The ovary ripens into a membranous capsule, bursting by three valves to liberate numerous flattish or globose seeds.
Most yams contain an acrid principle that is dissipated in cooking.
D. trifida and D. alata are the edible species most widely diffused in tropical and subtropical countries. D rotundata and D. cayenensis are the main yam species grown in West Africa. D. esculenta, grown on the subcontinent of India, in southern Vietnam, and in the South Pacific islands, is one of the tastiest yams. D. batatas, the Chinese yam, or cinnamon vine, is widely cultivated in East Asia. Hundreds of species of yams are known, and they vary widely in taste and appearance.