Jamssit – Dioscorea

Economically important edible yam species of African origin are white Guinea yam (D. rotundata), yellow Guinea yam (D. cayennensis), and trifoliate or bitter yam (D. dumetorum). Edible species from Asia include water or greater yam (D. alata), and lesser yam (D. esculenta) and Chinese yam (S. opposita). The air potato (D. bulbifera) is native to both Africa and Asia. The Cush-cush yam (D. trifida) originated from the Americas. Yam is cultivated mainly in the tropics, some species also in the subtropics. The species vary between geographical regions.