This is tamarind. It can be used in traditional Chinese medicine. Tamarind (Tamarindus indica), also known as sour bean, sour horn, sour son, nine layers of skin, Thai sweet horn, sour plum tree, Yasengo, is the only species of the genus Tamarindus in the family Leguminosae, a tropical tree native to eastern Africa, including the deciduous forests of Madagascar, but it has been introduced to the tropical regions of Asia, Latin America and the Caribbean. The tamarind tree is the city tree of Sanya, Hainan Province, China. The tamarind is best suited to areas with high temperatures, long sunshine, dry climates, and distinct wet and dry seasons. The flesh of the tamarind fruit is rich in sugar, acetic acid, tartaric acid, anthranilic acid, citric acid, etc. It is mainly used in the food field to make condiments, beverages, jams and so on.