Onion

Onion in the general sense can be used for any plant in the Genus Allium but used without

qualifiers usually means Allium cepa, also called the garden onion. Onions (usually but not

exclusively the bulbs) are edible with a distinctive strong flavour and pungent odour which is

mellowed and sweetened by cooking. They generally have a papery outer skin over a fleshy, layered

inner core. Used worldwide for culinary purposes, they come in a wide variety of forms and colours.

Onions may be grown from seed or very commonly from "sets". Onion sets are produced by

sowing seed very thickly one year, resulting in stunted plants which produce very small bulbs.

These bulbs are very easy to set out and grow into mature bulbs the following year, but they have

the reputation of producing a less durable bulb than onions grown directly from seed and thinned.

Either planting method may be used to produce spring onions or green onions, which are just

onions harvested while immature, although "green onion" is also a common name for the Welsh onion,

Allium fistulosum which never produces dry bulbs.

Onions are frequently used in school science laboratories because they have particularly

large cells which are easily visible even through rather low-end optical microscopes.

It is thought that bulbs from the onion family have been utilised as a food source for

millennia. In Palestinian Bronze Age settlements, traces of onion remains were found alongside fig

and date stones dating back to 5000 BC. It would be pure conjecture to suggest these were

cultivated onions. The archaeological and literary evidence suggests cultivation probably took

place around two thousand years later in ancient Egypt. This happened alongside the cultivation of

leeks and garlic and it is thought that workers who built the pyramids were fed radishes and

onions.

The onion is easily grown, transportable, and has good storage qualities. Egyptians

worshipped it, believing that its spherical shape and concentric rings symbolized eternal life.

Onions were even used in Egyptian burials as evidenced by onion traces being found in the eye

sockets of Ramesses IV. They believed that if buried with the dead, the strong scent of onions

would bring breath back to the dead. The onion then made its way to Greece where athletes ate large

quantities of onion because it would lighten the balance of blood. Roman gladiators were also rubbed

down with onion to firm up their muscles. In the Middle Ages onions were such an important food that

people would pay for their rent with onions and even give onions as gifts. Doctors were also known

to prescribe onions to end headaches, snakebites and hair loss. The onion was introduced to North

America by Christopher Columbus on his 1493 expedition to Haiti.