Indian Sandalwood

Santalum album is an evergreen tree that grows between 4–9 metres (13–30 feet). The tree is variable in habit, usually upright to sprawling, and may intertwine with other species. The plant parasitises the roots of other tree species, with a haustorium adaptation on its own roots, but without major detriment to its hosts. An individual will form a non-obligate relationship with a number of other plants. Up to 300 species (including its own) can host the tree's development—supplying macronutrients phosphorus, nitrogen and potassium, and shade—especially during early phases of development. It may propagate itself through wood suckering during its early development, establishing small stands. The reddish or brown bark can be almost black and is smooth in young trees, becoming cracked with a red reveal. The heartwood is pale green to white as the common name indicates. The leaves are thin, opposite and ovate to lanceolate in shape. Glabrous surface is shiny and bright green, with a glaucous pale reverse. Fruit is produced after three years, viable seeds after five. These seeds are distributed by birds.

Sandalwood is originally native to dry areas in India, Indonesia (Java and the Lesser Sunda Islands), the Philippines, and Western Australia, where it is found with close congeners. It was introduced very early (c. 1500 BCE) into Dravidian regions of South Asia via the Austronesian maritime spice trade, along with other Austronesian domesticates like areca nut and coconuts. It first appears in archaeological records in South Asia in the southern Deccan by 1300 BCE. It became naturalized in these regions where dry sandy soils are common. Sandalwood is now cultivated in India, Sri Lanka, Indonesia, Malaysia, the Philippines and Northern Australia.

S. album has been the primary source of sandalwood and the derived oil. These often hold an important place in the societies of their naturalised distribution range. The central part of the tree, the heartwood, is the only part of the tree that is used for its fragrance. It is yellow-brown in colour, hard with an oily texture and due to its durability, is a preferred material for carving. The outer part of the tree, the sapwood, is unscented. The sapwood is white or yellow in colour and is used to make turnery items. The high value of sandalwood has led to attempts at cultivation, this has increased the distribution range of the plant. It was valued in construction, since it was considered rot-proof. The first extraction of its essential oil occurred in Mysore, India, in 1917. For many years, the oils were extracted in the perfumeries at Grasse, France. Production and trade in India are governed by state-specific regulations, while privately established plantations have expanded following regulatory reforms introduced since the early 2000s. The ISO standard for the accepted characteristics of this essential oil is ISO 3518:2002. …

Sandalwood oil consists of about 80% α-santalol and β-santolol, predominantly the former, which are sesquiterpenes. Attempts to synthesise these date to 1947 by Givaudan in Switzerland. The resulting isobornyl cyclohexanol can be distinguished from santalol, but is much cheaper. Since then other synthetic sandalwood oils have been used in laundry detergents and textiles. Three of the terpene synthase genes producing components employed in host defense are present in S. album.