The onion (Allium cepa), which is also known as the bulb onion, common onion 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. Onion is most frequently a biennial, although it can also be a triennial or a perennial.
The vast majority of cultivars of A. cepa belong to the "common onion group" (A. cepa var. cepa) and are usually referred to simply as "onions". The Aggregatum Group of cultivars (A. cepa var. aggregatum) includes both shallots and potato onions.
Allium cepa is known exclusively in cultivation, but related wild species occur in Central Asia. The most closely related species include Allium vavilovii (Popov & Vved.) and Allium asarense (R.M. Fritsch & Matin) from Iran. However, Zohary and Hopf warn that "there are doubts whether the A. vavilovii collections tested represent genuine wild material or only feral derivatives of the crop."
Read more about Onion: Medicinal Properties and Health Effects of Onions, Eye Irritation, Propagation, Storage, Production Trends
Famous quotes containing the word onion:
“I had rather munch a crust of brown bread and an onion in a corner, without any more ado or ceremony, than feed upon turkey at another man’s table, where one is fain to sit mincing and chewing his meat an hour together, drink little, be always wiping his fingers and his chops, and never dare to cough nor sneeze, though he has never so much a mind to it, nor do a many things which a body may do freely by one’s self.”
—Miguel De Cervantes (1547–1616)
“Three meals of thin gruel a day, with an onion twice a week, and half a roll on Saturdays.”
—Charles Dickens (1812–1870)
“Let onion atoms lurk within the bowl,
And, scarce suspected, animate the whole.”
—Sydney Smith (1771–1845)