Aquilaria crassna

Aquilaria crassna is a species of plant in the Thymelaeaceae family. It is found in throughout Southeast Asia and in New Guinea. Aquilaria crassna is one source of agarwood, a resinous heartwood, used for perfume and incense. The resin is produced by the tree in response to infection by a parasitic ascomycetous mould, Phaeoacremonium parasitica, a dematiaceous (dark-walled) fungus.