Tectona grandis (teak)
Flower of Tectona grandis
IUCN status of Least Concern (LC).
This species naturally occurs in deciduous forests, but is planted commonly along roadsides and in large plantations throughout the tropics.
Building material, medicinal.
About this species
Tectona grandis (teak) is a tall tree from southeast Asia and is widely cultivated for its durable wood. It is a member of the mint family (Lamiaceae), which is perhaps better known for its aromatic members including culinary herbs such as basil, oregano and rosemary.
Geography and distribution
Tectona grandis has a natural distribution from India to Vietnam and Thailand. It is also found in cultivation throughout the tropics.
Teak is a tree up to 40 m high.
The bark is scaly and the leaves are opposite one another.
The leaves are 6 – 75 cm long, 8 - 45 cm wide, and hairless on the upper surface when mature, with many star-shaped hairs below.
The calyxes (sepals) form a balloon-like shape enveloping the fruit.
The corolla (petals) is regular, and white to cream-coloured.
The fruit is pale yellow, of 1.2 to 2 cm diameter, and covered with star-shaped hairs.
Threats and conservation
Although the species itself is common, the unique teak forests of India, Burma and Thailand are under threat from over-exploitation.
Tectona grandis is the source of a high quality general purpose hardwood known as teak. The timber is used for ship decking, flooring, furniture and construction. It is particularly recommended for construction in seaside environments (such as bridges and docks) because it is resistant to shipworm, a wood-boring sea mollusc (Teredo spp., Teredinidae). Quinones in the sawdust inhibit the growth of several species of the fungi that cause wood rot.
Teak has traditionally been used in southeast Asia for medicine, commonly for its astringent and diuretic properties and against swelling. Its traditional use for diabetes has been supported by laboratory tests in which extracts of the bark have been shown to lower insulin resistance in mice. The wood has also been said to relieve skin irritations caused by handling cashew nuts (Anacardium occidentale, Anacardiaceae) and marking nuts (Semecarpus anacardium, Anacardiaceae).
Millennium Seed Bank: Seed storage
Kew's Millennium Seed Bank Partnership aims to save plant life world wide, focusing on plants under threat and those of most use in the future. Seeds are dried, packaged and stored at a sub-zero temperature in our seed bank vault.
Collections stored in the Millennium Seed Bank: One
Seed storage behaviour: Orthodox - the seeds of this plant survive being dried without significantly reducing their viability, and are therefore amenable to long-term frozen storage such as at the MSB
Composition values: Oil content 34%
Tectona grandis grows best in a warm, tropical climate with a temperature above 22 ºC. Teak prefers well-drained, fertile soils and is a strong light demander.
Trees are 96 to 100% self-incompatible. The species is hermaphroditic and pollinated by insects, especially bees. Propagation by seed involves pre-treatment to break the dormancy, involving wetting and drying the seed every 12 hours, over a period of two weeks. When seeds are sown in a mix of sand and coir, at 22 to 25ºC, germination will take place within two to four weeks. The germination rate is low, and teak seedlings need shading.
Vegetative propagation can be achieved by grafting and budding. Tissue cultures have also been developed for the propagation of teak.
Boley J.D., Drew A.P., Andrus R.E. (2009). Effects of active pasture, teak (Tectona grandis) and mixed native plantations on soil chemistry in Costa Rica. Forest Ecology and Management. 257: 2254-2261.
Bonnington C., Weaver D., Fanning E. (2009). The use of teak (Tectona grandis) plantations by large mammals in the Kilombero Valley, southern Tanzania. African Journal of Ecology. 47: 138-145.
Derwisch S., Schwedenmann L., Olschewski R., Holscher D. (2009). Estimation and economic evaluation of aboveground carbon storage of Tectona grandis in Western Panama. New Forests. 37: 227-240.
Ghaisas M., Navghare V., Takawale A., Zope V., Tanwar M., Deshpande A. (2009). Effect of Tectona grandis Linn. on dexamethasone-induced insulin resistance in mice. Journal of Ethnopharmacology. 122: 304-307.
Nadkarni A.K. (1976). Indian Materia Medica. Volume 1. 3rd edn. Popular Prakashan, Bombay.
Soerianegara I, Lemmens RHMJ (1993). Plant Resources of South-East Asia 5(1). Timber trees: Major commercial timbers. Pudoc, Wageningen.
Sumthong P., Romero-Gonzalez R.R., Verpoorte R. (2008). Identification of anti-wood rot compounds in teak (Tectona grandis L.f.) sawdust extract. Journal of Wood Chemistry and Technology. 28: 247-260.
Warrier P.K. (1996). Indian Medicinal Plants: a Compendium of 500 Species. Orient Longman, Hyderabad.
Kew Science Editor: Rogier de Kok
Kew contributors: Olwen Grace (Sustainable Uses Group)
Copy editing: Emma Tredwell
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