Onions (academic: allium cepa l.) are two-year-old grass plants. The root of the onion is a stringed root; the tubing is cone-shaped, condensed in short length; and the cylindrical form of the leaf is the strongest, narrowest, shorter than the flower, and more than 0. 5 cm thick. The leaves are thick in size and dense around the trough, forming the spasm. Colours are purple, pink, brass, yellow or white. The figs are may-july. China was introduced earlier than the third century a. D., when west han opened the silk road, and it was called “onions”, i. E. Onions, because it was foreign. It is produced in western asia and cultivated throughout china and supplied throughout the four seasons. Onions were grown from ancient egyptian times and then spread to various regions by spanish colonizers, but mainly in temperate areas such as italy, mexico, spain and the united states. Onions are drought-resistant, wet, fertile, intolerant to high temperatures, strong light, drought and infertile, of good quality and high yield, and are grown widely with seeds, which are easy to store and connected and suitable for family gardens. Onions are recognized abroad as queens of food and are of high nutritional value. Onions can be used as food spices, and pearl onions are usually used as an add-on or spice in cocktails. At the same time, onion-specific irritating fragrances such as dithopropene can promote metabolism. Eating onions also gives people energy and eliminates fatigue. It also causes gastrointestinal discomfort. Onions are rich in nutrients and are spicy because they contain volatile substances. Modern medical evidence has shown that onions are resistant to disease, promote appetite, have stronger fungicide, blood pressure, prevention of arterial sclerosis, and apply to therapeutic feeding for vitamin c deficiency. Chinese doctors believe that onions have the effect of heating and deworming。
