What is the difference between sweet potatoes and yams? I’ve always thought they were one and the same.

Sweet potatoes are a dicot (double embryonic seed leaf) plant from the morning glory family. There are many varieties of sweet potatoes with skin colors that can range from white to yellow, red, purple or brown. The flesh also ranges in color from white to yellow, orange or orange-red. Sweet potato varieties are classified as either “firm” or “soft.” When cooked, the firm varieties remain firm, while soft varieties become soft and moist.

Yams are a monocot (single embryonic seed leaf) plant closely related to lilies and grasses. Native to Africa and Asia, yams vary in size from the size of a small potato up the record size of 130 pounds. Yams are starchier and drier than sweet potatoes. So why the name confusion? In the early United States, firm varieties of sweet potatoes were produced before soft varieties. When soft varieties were first commercially grown, there was a need to differentiate between the two. African slaves had already been calling the “soft” sweet potatoes “yams” because they resembled the yams in Africa. So, “soft” sweet potatoes were referred to as “yams” to distinguish them from firm varieties. Soft sweet potatoes may be labeled yams when sold in most produce sections, but they are true sweet potatoes. True yams are not generally sold in most U.S. supermarkets but can be found in international markets such as urban wholesale produce markets.