Yams a.k.a. sweet potatoes (photo by Jérôme Sautret via Wikimedia Commons)
The other day I was eating a yam and wondered where the name “yam” came from. The Oxford English Dictionary said the word is from West Africa and it’s not the name of the plant I was eating.
True yams are in the Dioscoreaceae family. Native to Africa and Asia, there are many cultivated varieties. Our yams were named by African slaves who saw the resemblance to their yams back home. A true yam (African type) looks like this.
True yams in Brixton market (photo from Wikimedia Commons)
North America does have native members of the Dioscoreaceae family but we don’t eat them. Have you ever seen these leaves in the woods, often in a whorl? Wild yamroot (Dioscorea villosa) is common in western Pennsylvania.
Wild yamroot leaves (photo by Tim McCormack from Wikimedia Commons)
The yams we eat are Ipomoea batatas. They’re labeled Yams in the grocery store because of USDA rules. White inside = “sweet potato.” Orange inside = “yam.” They’re the same plant.
Should we call them sweet potatoes instead? Well, that’s not accurate either. They’re not in the same family as potatoes (Solanaceae family).
The Ipomoea batatas flower gives us a clue to its identity. What family does this look like?
Ipomoea batatas flower (photo from Wikimedia Commons)
Yes, our sweet-potato-yam is a member of the morning glory family, Convolvulaceae.
I’ll call it a yam so I can find it in the grocery store.
Read more here at the Huffington Post: What’s the difference between sweet potatoes and yams?
(photos from Wikimedia Commons. Click on the images to see the originals)