1. Autumn lettuce planted in Henan Province should be planted in early and middle August, and its seedling period is in the high temperature season, so the seeds are not easy to germinate and the seedling Yi Bai is long. At the same time, high temperature and long sunshine are easy to promote flower bud differentiation and cause early bolting.

2. Lettuce (scientific name: Linn. ) is an annual or biennial herb in Compositae. It is 25- 100 cm high, the stem is upright and solitary, the basal leaves and the lower stems and leaves are large and undivided, oblanceolate, oval or elliptical, with a sharp tip, a short cone or a circle, and no stalk. The leaves on the lower part of the spike and the upper part of the spike are extremely small, egg-shaped and heart-shaped, and sessile. The heads are numerous or extremely numerous, arranged in panicles at the top of stems and branches. Achenes are oblanceolate, compressed, light brown, sharp-pointed, and slender, almost as long as achenes. The flowering and fruiting period is from February to September.