ABOUT TEAK AND ITS VARIETIES
The scientific classification of Teak
Following is the classification of Teak in the Plant Kingdom:
Kingdom: Plantae, Clade: Angiosperms, Eudicots, Asterids
Order: Lamiales, Family: Lamiaceae (earlier in Verbenaceae)
Genus: Tectona, Species: grandis, hamiltoniana, philippinensis
The word teak comes from the names: Tekku (in Tamil), Thekku (in Malayalam) via Teca (in Portugese).
The plant is known in Sinhala (Srilanka) as Thekka and Segun (in Bangladesh).
DESCRIPTION OF TEAK
Teak is a large, deciduous tree up to 40 m (131 ft) tall with gray to grayish brown branches.
Leaves are ovate-elliptical to ovate, 15–45 cm (5.9–17.7 in) long by 8–23 cm (3.1–9.1 in) wide, and are held on robust petioles that are 2–4 cm (0.8–1.6 in) long. Leaf margins are entire.
Fragrant white flowers are borne on 25–40 cm (10–16 in) long by 30 cm (12 in) wide panicles from June to August.
The corolla tube is 2.5–3 mm long with 2 mm wide obtuse lobes. Tectona grandis sets fruit from September to December; fruits are globose and 1.2-1.8 cm in diameter
Flowers are weakly protandrous in that the anthers precede the stigma in maturity and pollen is shed within a few hours of the flower opening.Flowers are weakly protandrous in that the anthers precede the stigma in maturity and pollen is shed within a few hours of the flower opening.
The flowers are primarily entomophilous (insect-pollinated), but can occasionally be anemophilous (wind-pollinated).]A 1996 study found that in its native range in Thailand, the major pollinator were species in the Ceratina genus of bees.
Heartwood is yellowish in colour. It darkens as it ages sometimes there are dark patches on it. There is a strange scent in newly cut wood.
Sapwood is whitish to pale yellowish brown in colour. It can easily separate from heartwood.
Wood texture is hard and ring porous and density is 720 kg/m3.
DISTRIBUTION AND HABITAT
Tectona grandis is one of three species in the genus Tectona.
The other two species, T. hamiltoniana (Burma teak) and T. philippinensis (Philippine teak), are endemics (They grow only in their respective countries and nowhere else in the world) with relatively small native distributions in Myanmar and the Philippines, respectively.
Tectona grandis is native to India, Sri Lanka, Indonesia, Myanmar, northern Thailand, and northwestern Laos.
Tectona grandis is found in a variety of habitats and climatic conditions from arid areas with only 500 mm of rain per year to very moist forests with up to 5,000 mm of rain per year. Typically, though, the annual rainfall in areas where teak grows averages 1,250-1,650 mm with a 3-5 month dry season.
Tectona grandis is a tropical hardwood tree species placed in the flowering plant family Lamiaceae.It’s a large, deciduous tree that occurs in mixed hardwood forests. It has small, fragrant white flowers and large papery leaves that are often hairy on the lower surface.
Teak wood has a leather-like smell when it is freshly milled. It is particularly valued for its durability and water resistance, and is used for boat building, exterior construction, veneer, furniture, carving, turnings, and other small wood projects. Tectona grandis is native to south and southeast Asia,mainly India, Sri Lanka, Indonesia, Malaysia, Thailand, Myanmar and Bangladesh but is naturalized and cultivated in many countries in Africa and Caribbean. Myanmar's teak forests account for nearly half of the world's naturally occurring teak. Molecular studies show that there are two centres of genetic origin of teak; one in India and the other in Myanmar and Laos.
Teak's natural oils make it useful in exposed locations and make the timber termite and pest resistant. Teak is durable even when not treated with oil or varnish. Studies have shown that plantation teak performs on par with old-growth teak in erosion rate, dimensional stability, warping, and surface checking. Teak consumption raises a number of environmental concerns, such as the disappearance of rare old-growth teak. However, its popularity has led to growth in sustainable plantation teak production throughout the seasonally dry tropics in forestry plantations. Propagation of teak via tissue culture for plantation purposes is commercially viable.
Teak's high oil content, high tensile strength and tight grain make it particularly suitable where weather resistance is desired.
It is used in the manufacture of outdoor furniture and boat decks.
It’s also used for cutting boards, indoor flooring, counter-tops and as a veneer for indoor furnishings. Although easily worked, it can cause severe blunting on edged tools because of the presence of silica in the wood. Over time teak can weather to a silvery-grey finish, especially when exposed to sunlight.
Teak is used extensively in India to make doors and window frames, furniture, and columns and beams in old type houses. It is resistant to termite attacks and damage caused by other insects. Mature teak fetches a very good price. It is grown extensively by forest departments of different states in forest areas.
Leaves of the teak wood tree are used in making Pellakai gatti (jackfruit dumpling), where batter is poured into a teak leaf and is steamed. This type of usage is found in the coastal district of Udipi in the Tulunadu region in South India. The leaves are also used in Gudeg, a dish of young jackfruit made in Central Java, Indonesia and gives the dish its dark brown color. Teak is used as a food plant by the larvae of moths of the genus Endoclita including E. aroura, E. chalybeatus, E. damor, E. gmelina, E. malabaricus, E. sericeus and E. signiferand other Lepidoptera including Turnip moth.
Teak is propagated mainly from seeds. Germination of the seeds involves pretreatment to remove dormancy arising from the thick pericarp. Pretreatment involves alternate wetting and drying of the seed. The seeds are soaked in water for 12 hours and then spread to dry in the sun for 12 hours. This is repeated for 10–14 days and then the seeds are sown in shallow germination beds of coarse peat covered by sand. The seeds then germinate after 15 to 30 days. Clonal propagation of teak has been successfully done through grafting, rooted stem cuttings and micro propagation. While bud grafting on to seedling root stock has been the method used for establishing clonal seed orchards that enables assemblage of clones of the superior trees to encourage crossing, rooted stem cuttings and micro propagated plants are being increasingly used around the world for raising clonal plantations.
WORLD'S LARGEST LIVING TEAK TREES
Ministry of Environmental Conservation and Forestry (Myanmar) found out two world’s biggest living teak trees on 28 August 2017 in Homalin Township, Sagaing region, Myanmar. The biggest one, named Homemalynn 1, is 27.5 feet (8.4 m) in girth and 110 feet (34 m) tall. The second biggest one, named Homemalynn 2, is 27 feet (8.2 m) in girth. Previously, the world's biggest recorded teak tree was located within the Parambikulam Wildlife sanctuary in the Palakkad District of Kerala in India, named Kannimara. The tree is approximately 47.5 m tall. In 2017, a tree was discovered in the Ottakallan area of Thundathil range of Malayattoor Forest Division in Kerala with a girth of 7.65 meters and height of 40 meters. A teak tree in Kappayam, Edamalayar, Kerala which used to be considered as the biggest, has a diameter of only 7.23 meters.
The International Teak Information Network (Teaknet) supported by the Food and Agriculture Organization (FAO) Regional office for Asia-Pacific, Bangkok, currently has its offices at the Kerala Forest Research Institute, Peechi, Thrissur, Kerala State in India. Teaknet is an international network of institutions and individuals interested in teak. Teaknet addresses the interests of all the categories of stakeholders related to teak, whether they are growers, traders, researchers or other groups with a profound interest or concerned with teak. From time to time, the organization formulates action plans focusing on the short term and long term needs of the global teak sector. The TEAKNET websiteprovides information to all those concerned with research, conservation, growing, management and utilization of teak.