What is the difference between sweet potatoes and yams? I make a sweet potato pie with yams. I don’t think I have actually tasted a sweet potato. Can they be substituted for each other? —P.H., Cardiff by the Sea, CaliforniaSweet potatoes and yams are similar in many ways, so they’re often confused with one another. To add to the confusion, canned sweet potatoes are often labeled yams. The sweet potato is a member of the morning glory family and native to Central America. Two varieties are readily available. One has a pale skin with a light yellow flesh and a dry mealy texture. The other has dark skin with a dark orange flesh that cooks to a moist texture. This variety is often commonly known as a yam. True yams, though, are not readily available in this country and are seldom grown here. However, they are available throughout Latin America, Asia, India, West Africa, the South Pacific and the Caribbean. Though you’re not likely to find true yams at your grocery store, yams and sweet potatoes are interchangeable in most recipes.