Teak

Tectona grandis

Physical Characteristics

Tectona grandis is a deciduous Tree growing to 30 m (98ft) by 20 m (65ft) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 10 and is frost tender. The flowers are pollinated by Bees, Flies, Ants. The plant is not self-fertile. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils and can grow in very alkaline soils. It cannot grow in the shade. It prefers moist soil and can tolerate drought.

Distribution

E. Asia - Indian subcontinent, Myanmar, Thailand, Laos, Cambodia, Vietnam.

Habitats

Edible Uses

Edible Parts: Leaves Edible Uses: Colouring The leaves are added to the water in which unripe jackfruit is boiled prior to making the Javanese dish 'Gudeg'[301 ]. This adds a fresh, reddish colour to the jackfruit[301 ]. A red dye obtained from boiling the wood shavings of the tree has been used to colour Easter Eggs[301 ]. The leaves act as a host for Rhizopus spores in Tempeh manufacture[301 ].

Medicinal Uses

Antibilious Antiinflammatory Astringent Depurative Digestive Diuretic Dysentery Eczema Febrifuge Malaria Odontalgic Parasiticide Purgative Skin Stimulant Tonic Urinary Vermifuge A wood tar paste is made from the powdered wood by putting it into hot water. It is vermifuge; promotes digestion; is effective in relieving bilious headaches and tooth aches; reduces inflammations or eruptions of the skin[303 , 404 ]. The charred wood, soaked in poppy juice and made into a paste, has been used to relieve the swelling of the eyelids[303 , 404 ]. The wood has been used as a hair tonic[303 ]. An oil extracted from the roots is used to treat eczema, ringworms and inflammation[404 ]. The bark has been used as an astringent and in the treatment of bronchitis[303 , 404 ]. The flowers are diuretic. They are used to treat biliousness, bronchitis and urinary disorders[299 , 404 ]. The seeds are diuretic[299 , 404 ]. An oil extracted from the seeds promotes hair growth[404 ]. The leaves have a reputation of being diuretic, depurative, purgative, stimulant, antidysenteric and vermifuge. They are used in traditional medicine to treat anaemia, asthenia, fever and malaria, amoebiasis, schistosomiasis and tuberculosis[299 , 404 ]. Extracts of the leaves are reported to be effective against mycobacterium tuberculosis, to treat bleeding of larynx, trachea, bronchi, or lungs, and sore throat[404 ]. An oil extracted from the tender shoots is used against scabies in children[299 , 404 ].

Known Hazards

The fine dust produced in machining operations may cause irritation of the skin or bronchial asthma and rhinitis after inhalation; a well-functioning dust extractor fan is recommended. The substance responsible for the allergic reaction is probably the naphthoquinone desoxylapachol[299 ].