Yam Discussion From The Wise Encyclopedia

A tuber of African origin, allied to the sweet potato, but with moist texture and high sugar content, and a whitish to reddish color skin and greenish-yellow to reddish or orange tint flesh. There is a wide variation in shape. The yam closely resembles the sweet potato, but grows much larger; it is the tuberous root of a different plant.

From The Wise Encyclopedia of Cookery, 1971.