Lettuce, commonly known as leaf lettuce, also known as goose feather lettuce, mashed lettuce and lettuce, belongs to the genus Lettuce in Compositae. It is an annual or biennial herb crop with long obovate leaves and dense cabbage shape, which can be eaten raw, crisp and slightly sweet.

Lettuce likes cold environment, neither cold nor heat. The suitable growth temperature is 15℃-20℃, and the growth period is 90- 100 days. Seeds can tolerate low temperature and germinate at 4℃. The optimum germination temperature is 18-22℃, and almost no germination occurs above 30℃.

Edible value of lettuce;

Lettuce is rich in nutrients, including a large number of β-carotene, antioxidants, vitamin B 1, B6, vitamin E, vitamin C, a large number of dietary fiber, magnesium, phosphorus, calcium and other trace elements and a small amount of iron, copper and zinc. Strengthen the digestion and absorption of protein and fat, improve the blood circulation of the stomach, and eat lettuce often.