Allium's the onion genus, with about 1250 species, making it one of the largest plant genera in the world. They're perennial bulbous plants that produce chemical compounds (mostly cystein sulfoxide) that give them a characteristic onion or garlic taste and odor, and many are used as food plants. Allium's classified in family Alliaceae although some classifications have included it in the lily family (Liliaceae). Allium species occur in temperate climates of the northern hemisphere, except for a… (More on Allium)