benzoin (bĕnˈzoin, –zōĭn) [key] or benzoinum bĕnzoinˈəm, balsamic resin, the dried exudation from the pierced bark of various species of the benzoin tree ( Styrax ) native to Sumatra, Java, and Thailand; appearing as red-brown to yellow-brown tears. Because of its fragrant odor it is used in perfume and sometimes in incense. The benzoic acid present in it gives it value in medicine as an antiseptic, as a stimulant, and, in certain respiratory diseases, as an inhalant. Among the several varieties are Siam benzoin and Sumatra benzoin. Siam benzoin is considered finer, since it has a high content of benzoic acid; Sumatra benzoin contains cinnamic acid.