ALLIUM CEPA

Common name: Onion • Hindi: प्याज़ Pyaz • Manipuri: তিলহৌ Tilhou • Tamil: வெங்காயம் Vengayam

Botanical name: Allium cepa      Family: Alliaceae (Onion family)

Geographical distribution

The plant is widely cultivated throughout India.

Introduction

Onions have cylindrical, hollow leaves and an enlarged bulb that develops at ground level. The roots come off the bottom of the bulb. The flowers are produced in the second growing season (following a required "rest" period) in a rounded umbel (cluster with all flower stems originating from the same point) on a stalk 2-4 ft tall. The umbels, about 2 in in diameter and consisting of many small purplish flowers, are quite showy. There are hundreds of onion cultivars, differing in day-length requirement, skin color (white, brown, yellow, red, or purple), size (1-6 in or 2.5-15.2 cm in diameter), shape (globe-shaped, flattened or spindle-shaped), pungency and sweetness. Both pungency and sweetness (which are not mutually exclusive) are determined to a considerable extent by the chemical characteristics of the soil in which the onion is grown.The onion is known only in cultivation, but probably was developed from a wild ancestor that grows in western Asia. Onion seeds have been found in Egyptian tombs dated to 3200 BC, and some authorities believe the onion may have been one of the first vegetables domesticated by humans.

 Chemical composition

The bulbs contain a volatile oil. The oil contains disulfide. Its fresh juice also contains thiocyanic acid and thiocyanate.

Therapeutic uses

The juice of onion is said to stimulate hair growth. Onion has been shown to be antihypercholesterolemic, hypoglycemic, diuretic, antifungal, and antimicrobial.

Folk medicinal uses

Raw onion applied to stings or insect bites are an old remedy to help alleviate the symptoms. Onion juice with mustard oil is applied as a liniment over painful joints, inflammatory swellings and diseases. A compress made of a roasted bulb applied to inflamed or protruding piles gives certain relief.

Flowers and Fruits : November-February