Dimocarpus longan is commonly known as the longan It’s a tropical tree species that produces edible fruit. The emperor had demanded lychee and longan trees to be planted in his palace gardens in Shaanxi, but the plants failed. Four hundred years later, longan trees flourished in other parts of China like Fujian and Guangdong, where longan production soon became an industry. The warm, sandy-soiled conditions allowed for the easy growth of longan trees. In ancient Vietnamese medicine, the “eye” of the longan seed was pressed against snakebites to absorb the venom.