What is lettuce?

Summary: Lettuce is an annual and biennial herb in Compositae. Lettuce can be divided into leaf use and stem use. 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. Characteristics: Lettuce root system is shallow and dense, mostly distributed in 20 cm-30 cm soil layer. At the seedling stage, leaves alternate on shortened stems. Lettuce has many large leaves and feeds on leaves or bulbs. Lettuce for stem grows vigorously, and the shortened stem gradually stretches and expands. After flower bud differentiation, the stems and leaves continue to expand, forming a stout fleshy stem. Lettuce heads have yellow flowers, each inflorescence has about 20 flowers, which are self-pollinated and sometimes cross-pollinated. Achene, brown or silvery white fruit with crested hair. Variety: Lettuce for leaf and lettuce for stem. Leaf lettuce is divided into long leaf lettuce, wrinkled leaf lettuce and head lettuce.