The sweet potato is a dicotyledonous plant that belongs to the bindweed or morning glory family, Convolvulaceae. Its large, starchy, sweet-tasting, tuberous roots are a root vegetable. The young leaves and shoots are sometimes eaten as greens. The sweet potato is only distantly related to the potato and does not belong to the nightshade family, Solanaceae, but both families belong to the same taxonomic order, the Solanales. The sweet potato is botanically very distinct from a genuine yam (Dioscorea), which is native to Africa and Asia and belongs to the monocot family Dioscoreaceae.