For hundreds of years, sweet potatoes across the United States have been masquerading as "yams." The truth is most Americans have probably never eaten a real yam.
The reason “yams” and sweet potatoes taste the same to Americans is because they are the same. What producers and grocery stores in the US have been calling “yams” are actually sweet potatoes (Ipomoea batatas).
This confusion isn’t new. In a 1896 book, a professor of horticulture at Texas A&M urged Americans to stop using the word “yam” to label sweet potato varieties:
Real yams (of the genus Diascorea) are not grown commercially in the United States. You probably have to visit an international grocery store to find them.
Check out the video above to see what a real yam looks like and learn how its name became attached to an entirely different vegetable. You can find this video and all of Vox’s videos on YouTube.