Aquilaria crassna is a species of plant

Plant

Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...

 in the Thymelaeaceae

Thymelaeaceae

Thymelaeaceae is a cosmopolitan family of flowering plants composed of 50 genera and 898 species. It was established in 1789 by Antoine Laurent de Jussieu.Thymelaeaceae is in the order Malvales...

 family. It is found in throughout southeast Asia and in New Guinea

New Guinea

New Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...

.

Economics

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.