Sweet and sour corn, also known as Zizyphus jujuba, is mainly produced in Yunnan, southern provinces and Southeast Asian countries, with an altitude of no more than 1400 meters, dry slope wasteland, dry hot valley and other places. The fruit of Lithocarpus angustifolia is rich in 18 amino acids, vitamin B 1, B2, C, calcium, phosphorus, iron, strontium and other mineral nutrients, various organic acids, and high content of protein and soluble total sugar. Among them, the content of calcium ranks first among all fruits, so it is called "the king of calcium".

Sweet and sour hawthorn is a precious natural wild medicinal and edible resource, which can produce body fluid to relieve summer heat, clear away heat and detoxify. Folk food has a long history, which can cure diarrhea and flatulence, prevent scurvy and excessive bile, eliminate sore throat and help digestion. In tropical and subtropical countries and regions, sour hawthorn drinks and mixed sour hawthorn drinks are so popular that the Coca-Cola Company of the United States has also begun to study sour hawthorn.

Sweet and sour corn, also known as tamarind, (Dai language) and sour beans, is a tropical fruit and a specialty of low-heat valley areas in Yunnan. There are two kinds of sweet corn and sour corn.

Sweet and sour horns grow in Yuanmou, Binchuan, Yuanjiang and Xishuangbanna. Big tree. Up to 25 meters. Resistant to barren, drought and cold. The leaves are opposite, and the beans are slightly curved, with a width of1.5-2.5cm and a length of 5 5- 10/0cm. The flesh is brown. It contains protein 3. 1%, carbohydrate 7 1.8%, fiber 3.0%, vitamins c, a, B 1, B2, calcium, phosphorus and iron, among which the calcium content ranks first among all fruits.

Sweet and sour horns have the effects of cooling, stopping diarrhea, appetizing and strengthening the spleen. Directly taken orally, it can promote fluid production to relieve summer heat, relieve cough and phlegm, relieve sore throat and help digestion, clean and strengthen teeth, prevent and treat diarrhea, flatulence, paralysis, scurvy, kill human parasites, and slow down alcohol and Datura poison. If mixed with salt, it can be used as a liniment for rheumatism. It is a health food suitable for all ages.

In addition to fresh food, it can also be made into tamarind, sauce, chips, crystal powder, beverage granules and so on. When used as medicine, it can stop diarrhea and reduce fever, relieve summer heat and reduce fever, and the tender leaves can be eaten after bleaching, and can also be used as a precipitation agent.