Monday, January 16, 2012

Yes, Virginia, it really is a fruit

Fun botany fact of the day: A tomato is really a fruit, but it's also really a vegetable.

You've probably heard the first half of this one before, so let me actually explain it this time. Whether something is a fruit or a vegetable all depends on who you're asking. To a botanist, a tomato is a fruit; to a cook, it's a vegetable. The botanical definition of "fruit" and the culinary definition of "vegetable" refer to completely different, unrelated properties, so it's actually possible to be both a botanical fruit and a culinary vegetable at the same time.

A botanical fruit is the part of the plant that developed from the flower's ripened ovary (which almost always means that it contains seeds). Apples, peaches, pears, raspberries, oranges, kumquats, and durian are all botanical fruits and also culinary fruits. Tomatoes, squash, olives, green beans, bell peppers, corn kernels, wheat "berries", and pumpkins are also all botanical fruits, although they're culinary vegetables. Botanically, there's no such thing as a "vegetable".

A culinary fruit is a plant part that's sweet; a vegetable is a plant part that's not very sweet. Every culinary vegetable is some other plant part as defined botanically. Carrots and radishes are roots, lettuce and spinach are leaves, potatoes and yams are tubers, onions are bulbs, celery sticks are petioles (leaf-stalks), peas are seeds, and tomatoes are fruits. All of those are also vegetables. There's no contradiction there.

2 comments:

  1. I like this kind of distinction between culinary and botanical, especially when it comes to fruits. My students have rebelled against the idea of tomatoes as fruit, but they certainly are.

    Then I tell them that a fruit is anything that contains seeds, and the smartest of them will come up with bananas. I have to point out that the teensy little specks are actually what would have been seeds had some very clever ancient botanists not gotten those gigantic plantain seeds whittled down to size.

    They really rebel at the idea that cereal foods are fruits. But you're square on on the distinctions.

    Very nice blog!

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    Replies
    1. Thank you for the compliment! It certainly means something, coming from the writer of Niches.

      I find the culinary/botanical distinction incredibly helpful. Once I've convinced my reader to let me draw it, the idea of tomatoes as fruit usually becomes much more palatable (so to speak). It helps pull the idea out of "Wow, those botanists sure are kooky" territory and into the realm of sense!

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