Sweet and sour corn, also known as Suanzao, is mainly produced in Yunnan, southern provinces and Southeast Asian countries, and the altitude is not more than 1400 meters in dry slope wasteland, dry hot valley and other places. The fruit of Lithocarpus angustifolia is rich in 18 kinds of amino acids, vitamin B 1, B2, C, mineral nutrients such as calcium, phosphorus, iron, strontium, various organic acids, high content of protein, soluble total sugar, etc. Among them, the calcium content ranks first among all fruits, so it is called "the king of calcium".

Sweet and sour Fructus Crataegi is a kind of precious natural wild medicinal and food resources, which can promote the production of body fluid to relieve summer heat, clear away heat and detoxify. It has a long history of folk consumption, and can cure diarrhea and flatulence, prevent scurvy and excessive bile, eliminate sore throat and help digestion, etc. In tropical and subtropical countries and regions, sour Fructus Crataegi beverage and mixed sour Fructus Crataegi beverage are very popular, so that the Coca-Cola Company of the United States has also begun to study sour Fructus Crataegi.

Sweet and sour corn, also known as tamarind, "Muhan" (Dai language) and sour bean, is a tropical fruit that is a specialty of low-heat valley areas in Yunnan Province. There are two types: sweet corn and sour corn.

Sweet and sour horns grow in Yuanmou, Binchuan, Yuanjiang and Xishuangbanna. Big trees. Up to 25 meters. Resistant to barren land, drought and cold. The leaves are opposite, and the pods are slightly curved, with a width of1.5-2.5cm and a length of 5-10cm. The flesh is brown. It contains protein 3.1%,carbohydrate 71.8%, 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 horn has the effects of cooling and relieving diarrhea, stimulating appetite and invigorating spleen. Directly taken in the mouth, it can promote the production of body fluid to relieve summer heat, relieve cough and phlegm, relieve sore throat, 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 be made into tamarind, sauce, tablets, crystal powder and beverage granules. When used as medicine, it can relieve 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 water precipitation agent.