From The Art and Popular Culture Encyclopedia
The onion (Allium cepa), which is also known as the bulb onion, common onion and garden onion,Template:Citation needed is the most widely cultivated species of the genus Allium. The genus Allium also contains a number of other species variously referred to as onions and cultivated for food, such as the Japanese bunching onion (A. fistulosum), Egyptian onion (A. ×proliferum), and Canada onion (A. canadense). The name "wild onion" is applied to a number of Allium species.