Hold on to your hats, this one is a shocker. I’ve always believed that ‘sweet potato’ was just a cutesy name for the less than phonetically pleasing ‘yam’. Man, I was so far off, I wasn’t even in the right genus. In fact, in North America especially, there’s a very good chance that you’ve never eaten a true yam in your whole life. (which will make some people very happy)
Yams, of the Dioscorea genus, are grown in much of Africa and Asia. Sweet Potatoes, from the Convolvulaceae family, are a close relative of Morning Glory flowering vines. They came from tropical South America, but are now grown in the US and Canada for local markets.
The whole naming confusion started because they look pretty much the same. African slaves in the US recognized the sweet potato to resemble yams from home. When sweet potato producers needed to differentiate between the firm and soft varieties, the yam name got picked up and is commonly used (mistakenly) in supermarkets to this day. I strongly recommend calling the girl at the checkout a big-fat-liar next time you go shopping. She will appreciate being enlightened.
