What are the differences between yams and sweet potatoes?
Yams, from a different family of plant entirely, are dry and starchy. They are imported to the United States from the Caribbean. The confusion between the two names arose when the orange-fleshed sweet potato was introduced to the United States. At the time, producers wanted to distinguish it from the white variety. Farmers used the English version of the African word “nyami,” calling the orange sweet potatoes yams. Source: ces.ncsu.edu