Incense plays an important role in the religion of Egypt. Numerous scenes showing the burning of incense appear on the walls of tombs and temples. In most cases, incense is shown already burning on special altars or in incense holders, which often have the shape of an arm. Large numbers of them have been found, usually of bronze, from as early as the Old Kingdom. Sometimes the illustration shows the offerer throwing a pellet of incense onto a brazier, with a line of small circles depicting the path the pellet follows. Frankincense, a fragrant gum resin, comes from various types of trees ('Boswellia' and 'Commiphora pedunculate') which grow in countries to the south of Egypt. Egyptian texts relate that incense was acquired in the Negro countries and from Punt, but also from western Asia. The latter area probably acquired it via the trade routes. Depictions in the temple of Hatshepsut at Deir el-Bahari show incense trees being transported from Punt to Egypt.