Oud

Agarwood, aloeswood, eaglewood or gharuwood is a fragrant dark resinous wood used in incense, perfume, and small carvings. It is formed in the heartwood of aquilaria trees when they become infected with a type of mold (Phialophora parasitica). Prior to infection, the heartwood is odorless, relatively light and pale colored; however, as the infection progresses, the tree produces a dark aromatic resin, called aloes or agar as well as Oud, or Oodh  in response to the attack, which results in a very dense, dark, resin-embedded heartwood. The resin-embedded wood is valued in Indian-North Eastern culture for its distinctive fragrance, and thus is used for incense and perfumes. Its name is believed to have first and foremost Sanskrit origin, formed from ‘Aguru’. The aromatic qualities of Agarwood are influenced by the species, geographic location, its branch, trunk and root origin, length of time since infection, and methods of harvesting and processing.

Uninfected aquilaria wood lacking the dark resin

One of the main reasons for the relative rarity and high cost of agarwood is the depletion of the wild resource. Since 1995, Aquilaria malaccensis, the primary source, has been listed in Appendix II (potentially threatened species) by the Convention on International Trade in Endangered Species of Wild Fauna and Flora. In 2004, all Aquilaria species were listed in Appendix II; however, a number of countries have outstanding reservations regarding that listing.