The Kien tree, also known as Aquilaria, is a tropical tree native to Southeast Asia. It is best known for producing agarwood, a valuable resin used in perfumes, incense, and traditional medicine. The tree can grow up to 40 meters tall and thrives in humid, tropical climates. When the Kien tree is wounded, it produces a dark, aromatic resin as a defense mechanism. This resin is highly sought after and can be quite expensive, making the Kien tree economically significant. Overharvesting and habitat loss have led to concerns about its conservation status in the wild.