Sour bean is the only variety of leguminous sour bean, also called sour horn, and it is a tropical tree. It is native to East Africa, including Madagascar deciduous forest, but has been introduced to tropical Asia, Latin America and the Caribbean. English Tamarindus consists of Tarmar and indus, Tarmar means ripe jujube and indus means India. Sour bean is a traditional Chinese medicine. In winter and spring, the sky is clear and clear. Walking into the Dai village in Xishuangbanna, it is easy to see a kind of fruit tree that local people especially like-Zizyphus jujuba. It has a tall tree with a rough trunk and sparse branches, and a string of brown hooked pods hanging from the branches. At present, according to the investigation of experts from the Institute of African Thermodynamics of China Academy of Sciences, the quantity and quality of tamarind trees in Africa are superior to those in Hainan, so Africa is called the hometown of tamarind or the hometown of cats. Sour bean tree is a city tree in Sanya, Hainan Province, China.