There are two types of benzoin gum used in incense and perfumery, benzoin Siam and benzoin Sumatra. Benzoin Siam is obtained from Styrax tonkinensis, found across Thailand, Laos, Cambodia, and Vietnam. Benzoin Sumatra is obtained from Styrax benzoin grown on the island of Sumatra. Both varieties are anti-pathogenic resins, which are exuded from the tree when it is damaged.