金合欢属大约有1100种,大多数是灌木或小乔木,大量分布在澳大利亚、非洲、印度和美洲的干热的稀树草原和干燥地区,其他的金合欢树种如黑荆(Acacia mearnsii)既适宜于温带又适宜于热带的高地阴凉、潮湿的地区生长,是世界皮革工业原料单宁的一个资源。然而,在金合欢属中有三分之一是属于高温潮湿的湿热带低地的乡土树种, There are about 1,100 species of Acacia, mostly shrubs or small trees, abundantly distributed in dry and hot savannas and dry areas in Australia, Africa, India and the Americas, and other Acacia species such as Acacia mearnsii Suitable for temperate and suitable for tropical highland cool, humid growth, is the world’s tanning industry, a resource of raw materials. However, one third of acacias belong to the native tree species in hot and humid lowlands of the tropics,