What’s the difference between a grain and vegetable?

I should have seen that one coming! Thanks, reader Clare. Grains are the seeds of grasses. Vegetables are…well, there isn’t a strict definition of what vegetables are. A vegetable can be any edible part of a plant that’s not a) the seed or b) the ripened ovary. The ripened ovaries of seed-bearing plants are what are known in scientific terms as “fruits”, if you follow me. Thus you can see why tomatoes and squash are classified as fruits and not a vegetables: they have seeds.

So then why isn’t corn a fruit? Aren’t the individual kernels the seeds? Alright smarty pants, yes, they are. But only when they’re dried. Which means that when an ear of corn is dried out it’s technically a fruit, with the individual kernels being the seeds and the cob being the ovary. However prior to that point, i.e. when the kernels are in their raw or “milky” stage, they aren’t seeds, they’re a non-seed edible structure, which is a vegetable.

So then if the kernels become the seeds, does’t that mean corn really is a grain after all? OK clever dick, yes, it does. Given that corn’s wild ancestor, teosinte, is a grass, that makes corn a grain in the eyes of many people.

So then why do I insist on calling corn a vegetable? In part because the kernels intuitively seem more like “edible structures” to me than seeds. But more concretely, because of corn’s nutritional profile. Corn provides vitamins A, C and E, but lacks most of the B vitamins — typical of a vegetable. Corn is also low in the proteins that true grains provide, especially lysine and tryptophan. So to me, if it looks like a duck and quacks like a duck then I’m on the side of the vegetarians…I mean, the vegetable people.

Of course there are those who insist that corn is all three things: a fruit AND a vegetable AND a grain. But those folks are just plain nuts. I mean…crazy.

6 thoughts on “What’s the difference between a grain and vegetable?”

  1. Ummm . . . I’m not going to disagree with you that sweet corn is a vegetable. Just as I wouldn’t disagree that squash is a vegetable. But it is my duty to correct your botany. 🙂

    I’m afraid that corn is most definitely a grain (and the corn plant is a grass). Corn on the cob isn’t a fruit; the cob is not part of the ovaries, but is the rachis (stalk) that holds the tight cluster of flowers that ripen into fruits. Yes: the individual corn kernels are, in fact, fruits. As are all whole grains. The technical term is “caryopsis”, which is a one-seeded fruit in which the ovary wall is tightly joined to the seed coat.

  2. Reader Arturo writes:

    Yeah, sorry, no. Maize (Indian corn), Zea mays belongs to the subfamily Panicoideae in the family Poaceae, formerly known as Gramineae. By definition, members of Panicoideae are grasses and the cultivated ones (mostly) are cereals, or in usual speech: grains. Vegetable, anyway, is not a botanical category but a cultural one. People treat different parts of unrelated plants as vegetables and then argue about some of them. Are mushrooms vegetables? Seaweed? Are tomatoes vegetables or fruits? Quinces? No doubt for people who eat corn on the cob or corn stews, maize is a vegetable but, botanically, it is a grain (cereal).

    1. Um on the genetic level mushrooms definitely ARE NOT vegetables, or even plants for that matter. They are fungus. Tomatoes are, on the genetic level, fruit.

      1. It was more of a rhetorical question, but thanks for clearing it up, Brandon! 😉

        – Joe

  3. Point taken! Jeez. Who knew botanists were such an uptight bunch? Can we at least agree that while botanically corn is a grain, nutritionally it’s a vegetable? That seems reasonable.

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