Teak(Tectona grandis), Verbenaceae

Introduction Teak is one of the most important timber plants of the world. The plant is native to India, Java, Sumatra, and parts of Indonesia. It is a large deciduous tree reaching a height of 30 meter and a girth of 4 meter. The tree has a age of 200 years. The branches are quadrangular and hairy. The leaves are opposite, simple, and elliptical to ovate. They are rough and covered by hairs. The flowers are arranged in large terminal panicle. Flowers are bracteate, bisexual, hypogynous and pentamerous. The fruits are hard bony nuts.

Area under cultivation Teak is widely grown in India, Burma, Sri lanka, Java, Sumatra and Indonesia. Extensive forests of Teak is found in Burma. In India Teak forests are usually found in MP., Maharashtra, Gujarat, Karnataka, Rajasthan, TN., Kerala and AP. The total area under Teak cultivation in India is about 7,276,000 ha.

CULTIVATION Teak grows in a variety of soils but requires perfect drainage. It is light demanding and requires a free circulation of air. The plants thrive well at a temperature of degree centigrade.An annual rainfall of cm. is also a requirement. Trees are stunted in a nitrogen deficient soil. Seedlings are raised in nursery beds in April and May in bright sun light as the seedlings do not like a shade.When the seedlings are 30 cm in height they are transplanted. A good timber is obtained from the trees when they are years old.

LEAVES AND FLOWERS

Teak in flowering stage

Properties of Teak wood Teak wood is differentiated into sap wood and heart wood. The sap wood is white to pale yellowish and the heart wood is golden yellow. The sap wood is susceptible to mites, termites and rotting fungi. The heart wood bear definite figure and luster and is resistant to mites, termites and wood decaying fungi. The wood is oily to touch and emits a characteristic odor of old leather. The grain is normally straight and the texture is very coarse and uneven. The average weight is about 650kg/m at 12% moisture content. The wood is a ring porous with distinct growth rings.

USE Teak is well known for its above ground durability, with a life expectancy of greater than 40 years. In-ground life expectancy ranges from 15 to 25 years. Teak exhibits a good resistance to acids, and will not corrode metal fixings. Teak is termite- resistant, although untreated sapwood is susceptible to borer attack. Teak is extensively used in boatbuilding for decking, rails, bulwarks, hatches, weather doors, and planking. It is also used for cooperage, pipes, and chemical vats. In general construction it is suitable for flooring, decking, framing, cladding, fascias and barge boards. Decorative uses of teak include indoor and outdoor furniture, parquetry, turnery, carving, lining and panelling.

Teak wood in tangential plane

Traditional use Bark: is used as astringent, constipation, anthelmintic and depurative. It is used in bronchitis, hyperacidity, dysentery, verminosis, burning sensation, diabetes, difficult labour, leprosy and skin diseases. Leaves: are cooling, haemostatic, depurative, anti-inflammatory and vulnerary. They are useful in inflammations, leprosy, skin diseases, pruritus, stomatitis, indolent ulcers, haemorrhages and haemoptysis. Wood: Acrid, cooling, laxative, sedative to gravid uterus, useful in treatment of piles, leucoderma and dysentery. Oil extracted from the wood is best for headache, biliousness, burning pains particularly over a region of liver. Roots: are useful in anuria and retention of urine