The Grammarphobia Blog

I yam a sweet potato

Q: I was watching a cooking show on TV and the chef got all upset about people who call sweet potatoes “yams.” Isn’t it just a regional thing from the South? Or another sense of the word?

A: Sweet potatoes and true yams are different, unrelated vegetables. Sweet potatoes come from the tropical Americas and yams from Africa and Asia, and they’re from different plant families.

Despite all that, what we call “yams” in this country (especially in the South and the West) are really sweet potatoes. How did the names of the sweet potato and yam get confused? An article by Jonathan R. Schultheis and L. George Wilson, horticultural scientists at North Carolina State University, explains it this way:

“Several decades ago, when orange-fleshed sweet potatoes were introduced in the southern United States, producers and shippers desired to distinguish them from the more traditional, white-fleshed types. The African word nyami, referring to the starchy, edible root of the Dioscorea genus of plants, was adopted in its English form, yam. Yams in the U.S. are actually sweet potatoes with relatively moist texture and orange flesh. Although the terms are generally used interchangeably, the U.S. Department of Agriculture requires that the label ‘yam’ always be accompanied by ‘sweet potato.’ “

The American Heritage Dictionary of the English Language (4th ed.) notes that the sweet potato is “also called regionally yam.” I’ve always heard the two terms used interchangeably, except when it comes to dessert. Sweet potato pie is always sweet potato pie in my experience, never “yam pie.”

As for the chef on that cooking show, he should relax. A sweet potato by any other name would taste as sweet. Or, as Popeye would say, “I yam what I yam.”

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