Aquilaria is a genus of eight species of trees in the Thymelaeaceae native to southeast Asia. They occur particularly in the rain forests of Indonesia, Thailand, Cambodia, Laos, Vietnam, Malaysia, and Northern India. The trees grow to 6-20 m tall. The leaves are alternate, 5-11 cm long and 2-4 cm broad, with a short acuminate apex and an entire margin. The flowers are yellowish-green, produced in an umbel; the fruit is a woody capsule 2.5-3 cm long.
The genus is best known as the principal producer of the resin-inpregnated agarwood, especially Aquilaria malaccensis. The depletion of wild trees from indiscriminate cutting for agarwood has resulted in the trees being listed and proteced as an endangered species. Projects are currently underway in some countries in southeast Asia to infect cultivated Aquilaria trees artificially to produce agarwood in a sustainable manner.
Aquilaria acuminata (Merr.) Quisumb., 1946, originally Gyrinopsis acuminata
Aquilaria apiculata Merr., 1922
Aquilaria baillonii Pierre ex Lecomte & Leandri, 1949
Aquilaria crassna Pierre ex Lecomte, 1915
Aquilaria filaria (Oken) Merr., 1950
Aquilaria grandiflora Benth., 1861
Aquilaria malaccensis, Lam., 1783, synonyms A. agallocha and A. secundaria
Aquilaria ophispermum Poir.
Aquilaria pentandra Blanco, 1837
Aquilaria rugosa K.Le-Cong & Kessler, 2005
Aquilaria sinensis Gilg, 1894
Aquilaria yunnanensis S.C.Huang, 1985
Agarwood is a resinous wood that sometimes occurs in trees belonging to the Aquilaria genus, Thymelaeceae family. Aquilaria is a fast-growing, archaic tropical forest tree, which occurs in South and Southeast Asia, from the foothills of the Himalayas to the rainforests of Papua New Guinea. The tree grows in natural forests at an altitude of a few meters above sea level to about 1000 meters, and it grows best around 500 meters. It can grow on a wide range of soils, including poor sandy soil. Seedlings need a lot of shade and water. Trees grow very fast, and start producing flowers and seeds as early as four years old.