What is the difference between a yam and a sweet potato?
Yams and sweet potatoes are different plants. True yams have rough, bark-like skin and starchy white flesh, while sweet potatoes have smooth skin and are sweeter.
Sweet potatoes belong to the morning glory family and originated in Central and South America. Their flesh can be orange, white or purple. True yams belong to a different family, Dioscoreaceae, and are native to Africa and Asia. They can grow very large, sometimes more than a meter long.
In the United States, orange-fleshed sweet potatoes are often sold as yams. The confusion dates to the mid-1900s, when growers used the name to distinguish soft, orange varieties from firmer, pale ones. US rules require these to be labeled as sweet potatoes too.
Where they are eaten
True yams are a staple food in West Africa, especially Nigeria, which grows most of the world's yams. They are often boiled, fried or pounded into a smooth dough called pounded yam.
Did You Know?
Sweet potatoes are rich in beta-carotene, the pigment that gives orange varieties their color and that the body turns into vitamin A.