After tasting produce you've brought home from the store, you might become such a fan of a certain vegetable that you consider growing it in your garden. Knowing what part of the plant the vegetable came from will give you some idea of what the plant itself might be like in your garden. Meanwhile, keeping in mind the major parts of a plant--roots, vegetative parts and flowers--helps you zero in on where a vegetable emerged.
Look for stems, leaves and/or stalks. If you find them, you're looking at a vegetable harvested from the vegetative parts of the plant. Celery is one such vegetable, along with collard greens and spinach.
Look closely for flower buds. This is made easier by trying to stand the vegetable up as it might have been in the ground. If you do this with broccoli, you'll find that the florets are actually masses of buds packed together. Cauliflower also has florets, so it too comes from a plant's flowering part.
Look for buds, eyes, sprouts and stems growing from the vegetable. If you find them, the vegetable is probably the plant's food storage organ, which grows underground. Tubers like potatoes and bulbs like onions are examples of these organs. So are radishes.
Cut open the vegetable and look for seeds and/or a core. If you find one or both of those, the vegetable is the fruit produced by a female flower. Flowers make seeds when pollination fertilizes eggs contained in the flower's ovary. The ovary, meanwhile, and, perhaps, other parts like the floral tube swell to become the flesh. Cucumbers and green beans are the fruits of flowers.