Do you celebrate National Peanut Day every September 13? Of course, we all do! It's a cruel coincidence that the peanut's big moment comes every fall, just as kids are returning to their increasingly peanut-free schools. If you're not allergic, you probably love peanuts in your trail mix, on sundaes, or in sandwiches (butter form only). But how much do you really know about the protein-rich foodstuff? Jeopardy!'s Ken Jennings is here to tell us that a lot of your favorite facts about this beloved snack are just plain nuts.
The Debunker: Are Peanuts Nuts?
Peanuts took a roundabout route to get to your kitchen cupboard. They were carved on pottery and left in Peruvian tombs five thousand years ago, and European settlers first ran across them in Brazil. Then the Portuguese spread them around the world, as far as Africa and China. But they didn't catch on in North America until African slaves returned them to the New World, planting them in Virginia. Dive bars and ballgames would never be the same again. In the 19th century, this new crop was often called the "ground nut" or the "ground pea"; our word "peanut" is a conflation of the two. But strictly speaking, peanuts are neither peas nor nuts.
Here's the scoop: nuts and legumes are very similar, but botanically speaking, they're not that hard to distinguish. A nut is a fruit whose ovary wall has hardened into a tough shell. It protects a single seed, and won't open on its own. A legume, on the other hand, is a pod that contains multiple seeds. Beans and peas are familiar legumes. And so are peanuts, despite their name. Peanuts plants flower above ground, just like nut trees, but then the withered blossoms sag under the soil. By the time the pods—the peanuts themselves—start to grow, they're an inch or two underground.
In culinary terms, of course, this doesn't matter so much. Peanuts are often eaten in the same way as real nuts. But the botanical difference explains why there's not always much overlap between peanut allergy and tree nut allergies. Does it also explain why almond butter is sort of gross when you try to sub it in for peanut butter in a sandwich? Maybe. Not my place to say.
Quick Quiz: What's the more common name for the butter bean, another legume introduced to North America and Europe from Peru?
Ken Jennings is the author of eleven books, most recently his Junior Genius Guides, Because I Said So!, and Maphead. He's also the proud owner of an underwhelming Bag o' Crap. Follow him at ken-jennings.com or on Twitter as @KenJennings.