Collapsed vegetable is a famous specialty in Anhui province, and it is a variety of Chinese cabbage. Its leaves are dark green and tender, so it is named after the collapse of the ground. Mainly distributed in the Yangtze River valley in China, it has the advantages of wide distribution, high yield, good flavor and long supply period. The main characteristics are: the plant is dark green, the petiole is short and flat, and the leaves are thick with blisters and bristles; The outer leaves grow in collapse, and the heart leaves tend to roll up in different degrees; Cold-resistant, can overwinter in the open air, and can be supplied to the market in winter and spring; Strong fragrance, first frost is soft and juicy after being covered with snow, with increased sugar and excellent quality, so there is an agricultural proverb that "vegetables collapse under the snow to compete with mutton". There are many varieties of it, mainly including Huangxinwu, Heixinwu, Baotawu, Ziwu, Baiwu and Mahu.