Onions and garlic are both members of the genus, Allium. These two pungent edible root crops have both culinary and medicinal uses. Garlic is native to central Asia, and has been cultivated for over 7,000 years. The leaves and flowers of garlic are also edible, although uses much less frequently than the tasty bulbs. Onions are also grown worldwide, mostly for culinary use. Onions excrete a strong chemical which stings and burns the eyes when onions are chopped, which is why people 'cry' when exposed to chopped onions.