(scientific name: Lactuca sativa), also known as spring lettuce, wheat lettuce, is an annual or biennial vegetable of the genus Lettuce in the family Asteraceae. It is a very common edible vegetable, people in China, Japan and other countries tend to cook it and eat it, and in Western cultures people tend to put it in salads, hamburgers and other foods to eat it raw. In Hong Kong, lettuce is also known as Tang lettuce to distinguish it from Western lettuce.

Lettuce, Asteraceae, lettuce genus, one or two-year-old herb. Lettuce can be divided into two categories: leaf and stem. Lettuce has many names, in the herb book called "thousand gold vegetable", "lettuce" and "stone chicory". Leaf lettuce is also known as spring vegetables, wheat lettuce, stem lettuce is also known as lettuce, bamboo shoots. Cultivated in China around the area of lettuce than lettuce, lettuce meat tender, stems can be eaten raw, cold, fried, dried or pickled. Lettuce is mainly eaten leaves or leaf ball, in recent years in the big cities, especially in the southern coastal provinces of the big cities have developed, become the current increase in fancy varieties of the main vegetables. Lettuce stems and leaves contain lettuce pigment, bitter taste, high temperature drought bitter flavor, can enhance gastric juice, stimulate digestion, enhance appetite, and has analgesic and hypnotic effect. In Hong Kong, in order to distinguish with the western lettuce, lettuce is also known as Tang lettuce.