Frankincense is an aromatic gum resin obtained by tapping the trunks of trees belonging to the genus Boswellia. The milky resin hardens when exposed to the air and forms irregular lumps—the form in which it is usually marketed. Also called olibanum, frankincense is used in pharmaceuticals, as a perfume, as a fixative, and in fumigants and incense. Myrrh comes from a tree of the genus Commiphora, a native of Arabia and Northeast Africa. It too is a resin obtained from the tree trunk and is used in pharmaceuticals, perfumes, and toothpaste.