Aquilaria is a genus of fifteen species of trees in the Thymelaeaceae, native to southeast Asia. They occur particularly in the rainforests of Indonesia, Thailand, Cambodia, Laos, Vietnam, Malaysia, Northern India, the Philippines, Borneo and New Guinea. 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.