Yam is the common name for some plant species in the genus Dioscorea (family Dioscoreaceae) that form edible tubers. These are perennial herbaceous vines cultivated for the consumption of their starchy tubers in Africa, Asia, Latin America, the Caribbean and Oceania. Yams are monocots, related to lilies and grasses.
Native to Africa and Asia, yam tubers vary in size from that of a small potato to over 1.5 meters in length and 70 kg in weight. There are over 600 varieties of yams and 95 percent of these crops are grown in Africa.