Lettuce , Asteraceae, Lactuca , 1. Biennial herb. Lettuce can be divided into two types: leaf and stem. Lettuce has many names, in this cursive it is called “qianjincai”, “lettuce” and “stone lettuce”. Lettuce for leaf is also called spring vegetable and lettuce , lettuce for stem is also called lettuce and bamboo shoot. The cultivated area of lettuce is more than lettuce in all parts of our country . The meat of lettuce is tender, and the stems can be eaten raw, cold, fried, dried or pickled. Lettuce mainly eats leaves or leaf balls. In recent years, it has developed in major cities, especially in the major cities of the southern coastal provinces, and has become the main vegetable for increasing fancy varieties. Lettuce stems and leaves contain lettuce, which has a bitter taste, high temperature, drought and strong bitterness, which can enhance gastric juice, stimulate digestion, increase appetite, and have analgesic and hypnotic effects.