There are many differences between sweet potatoes and yams. Sweet potatoes are roots of a vine in the morning glory family. Yams are tubers of a tropical vine. Sweet potatoes are rich in vitamin A while yams contain no vitamin A.

To make this issue more confusing, there are two types of sweet potatoes. The paler-skinned sweet potato has a thin, light yellow skin with pale yellow flesh, which is not sweet and has a dry, crumbly texture similar to a white baking potato. The darker-skinned variety (which is most often called “yam” in error) has a thicker, dark orange skin with a vivid orange, sweet flesh with a moist texture. U.S. supermarkets tend to carry both types of sweet potatoes but incorrectly label the darker-skinned variety “yams.”

True yams are rarely available in U.S. markets. If you find yams, they will most likely be sold in chunks sealed in plastic wrap, since they grow up to 7 feet in length and weigh up to 150 pounds! The yam tuber has a brown or black skin, which resembles the bark of a tree, and off- white, purple or red flesh, depending on the variety.