Lettuce is an annual or biennial herb in Compositae, belonging to the genus Lettuce. Lettuce can be divided into leaf use and stem use. Lettuce has many names. In this cursive script, it is called "thousand-seed dish", "lettuce" and "borage". Lettuce for leaves is also called lettuce, and lettuce for stems is also called lettuce and fragrant shoots. There are more lettuce than lettuce in all parts of China. Lettuce is tender, and its stems can be eaten raw, cold, fried, dried or pickled. Lettuce mainly eats leaves or bulbs. In recent years, it has developed in major cities, especially in southern coastal provinces, and has become the main vegetable to increase fancy varieties. Lettuce stems and leaves contain lettuce, which is bitter, hot and dry, bitter, can enhance gastric juice, promote digestion, stimulate appetite, and have analgesic and hypnotic effects.