The sweet potato (Ipomoea batatas), commonly calle a yam in parts of the United States (although they are not actually yams), is a crop plant whose large, starchy, sweet tasting tuberous roots are an important root vegetable. The young leaves and shoots are sometimes eaten as greens. The sweet potato is only distantly related to the potato (Solanum tuberosum). It is even more distantly related to the true yam (Dioscorea species), which is native to Africa and Asia.