Sweet Potatoes are large edible roots, native to tropical areas of the Americas. They are NOT members of the nightshade family. There are seven major varietiesÂ of sweet potatoes: Jersey, Kotobuki (Japanese), Okinawan (Purple), Papa Doc, Beauregard, Garnet, Jewel, and Covington. The last four varieties are regionally called yams in the United States.Â Two varieties are widely grown in the US: a pale sweet potato and a darker-skinned variety that Americans erroneously call "yam" (a true yam is not related to the sweet potato). True yams are not widely marketed and are seldom grown in the US; and to add to the confusion, canned sweet potatoes are frequently labeled as yams. The pale sweet potato has a thin, light yellow skin and a pale yellow flesh. Its flavor is not sweet and when cooked its flesh is dry and crumbly, much like a white baking potato. The darker variety has a thicker, dark orange skin and a vivid orange, sweet flesh that is much moister when cooked.Â Sweet potatoes are also known as kumara (or kumera) in New Zealand, batatas or boniatos in South America, umala by Samoans, and 'uala by Native Hawaiians. Kumara was a staple of the Maori in New Zealand prior to the arrival of Europeans, and is popular throughout the Pacific region.