Sweet acacia (Acacia farnesiana) belongs to Mimosaceae (the Mimosa family). It is a semi-tall evergreen tree that is thought to be native to southern United States and Mexico. It is planted widely or naturalized in the tropical and sub-tropical areas. This tree grows in arid pine communities and waste grounds, and can reach about 8 m in height. The barks are pale brown, coarse and the leaves are bipinnate compound with 10-12 pairs of broad-linear leaflets. The spherical clusters are borne on the long peduncles of axils, and bloom scented yellow flowers. The fruits are pods, 4-7.5 cm long, and do not split open. The barks and fruits contain tannin, and used as an ingredient of dyewood and ink.