Local names:
Burmese (sha), English (betel-nut palm,black cutch,catechu tree,cutch tree,heartwood), French (acacie au cachou), Hindi (khair,supari,sundra,cachu,koir,tallatuma), Malay (pinang), Nepali (khair,khaira), Sanskrit (khadir), Tamil (karungali,kamugu,paku,bag
Acacia catechu is a small or medium-sized, thorny tree up to 15 m tall; bark dark grey or greyish-brown, peeling off in long strips, or sometimes in narrow rectangular plates, brown or red inside; branches slender, puberlous when young but glabrascent, with 2 curved, 8-mm prickles at the base of each petiole. Leaves bipinnately compound, with 9-30 pairs of pinnae and a glandular rachis; leaflets 16-50 pairs, oblong-linear, 2-6 mm long, glabrous or pubescent. Flowers in 5-10 cm long axillary spikes, pentamerous, white to pale yellow, with a campanulate calyx, 1-1.5 mm long, and a corolla 2.5-3 mm long; stamens numerous, far exserted from the corolla, with white or yellowish-white filaments. Fruit a strap-shaped pod, 5-8.5 cm x 1-1.5 cm, flat, tapering at both ends, shiny, brown, dehiscent, 3-10 seeded; seeds broadly ovoid. In India, three varieties, namely: var. catechu, var. catechuoides and var sundra are recognized. The generic name, ‘acacia’, comes from the Greek word ‘akis’, meaning a point or a barb. The species name comes from 'cutch', a tanning extract isolated from its heartwood.
Ecology
A. catechu occurs naturally in mixed deciduous forests and savannas of lower mountains and hills. It is especially common in the drier regions on sandy soils of riverbanks and watersheds.
Native range
India, Myanmar, Nepal, Pakistan, Thailand
Tree management
Early growth is slow, and in Thailand the mean annual diameter increment is only 0.8-1.3 m. Weeding is essential, especially when the plants are still young. Protection against fire is necessary, especially in the drier parts of its range, and so is protection from grazing animals. Rotation regimes depend upon the intended use: for fuelwood production, felling is usually at 10-15 years of age; trunks with a diameter of 30-35 cm are considered the most economic. For extracting the tanning agent cutch, this size may not be achieved for 30 years.
Seed storage behaviour is orthodox. According to different authors, viability is lost within 1 year in hermetic storage at room temperature at 11-15% mc; viability is maintained for at least 2 years at ambient temperature; viability is maintained for 9 months in open storage at room temperature; viability can be maintained for several years in hermetic storage at 10 deg. C. There are 15 000-40 000 seeds/kg.
A. catechu occurs naturally in mixed deciduous forests and savannas of lower mountains and hills. It is especially common in the drier regions on sandy soils of riverbanks and watersheds.
A. catechu can be raised from direct sowing,coppice, planting out nursery-raised seedlings or by stump planting. It is recommended, but not necessary, to put the seeds in boiling water and then leave for 24 hours them to cool.
Poison: The bark is said to be toxic and contains an alkaloid and both fruit and stem are used in Myanmar to poison fish.
Seeds contain water-soluble mucilage (6.8%); a good protein source but nutritionally incomplete with respect to essential amino acids.
It is considered to be a good fodder tree and is extensively lopped to feed goats and at times cattle. For leaf fodder, finger-thick branches are lopped usually before main leaf fall occurs.
The wood is excellent firewood. The calorific value of sapwood is estimated at 5 142 kcal/kg, heartwood 5 244 kcal/kg. Dry wood on destruction gives 38.1% charcoal of very good quality.
Timber: Comparatively heavy with a density of 880-1 000 kg/cubic m at 15% mc. It is recommended to saw the comparatively heavy wood of A. catechu when green; the wood is also very strong, durable and resistant to white ants. Timber is used for house posts, agricultural implements and wheels. Spent chips left over after extraction of katha and cutch can be used for the manufacture of hardboards.
Tannin or dyestuff: A substance called cutch, which is marketed as a solid extract, can be isolated from the heartwood. Depending on the way of processing, several products can be obtained from crude cutch. The dark catechu or Pegu cutch is used to tan heavy hides into sole leather, often in a mixture of tan stuffs. Catechu extract is also used for dyeing silk, cotton, canvas, paper and leather to a dark-brownish colour.
Medicine: Khersal, a crystalline form of cutch sometimes found deposited in cavities of the wood is used medicinally for the treatment of coughs and sore throat. The bark is said to be effective against dysentery, diarrhoea and in healing of wounds. The seeds have been reported to have an antibacterial action. In East Africa, the powdered bark, mixed with sulphate of copper and egg yolk, is applied to cancerous growths.
Gum or resin: The bark exudes a light gum of very good quality and is one of the best substitutes for gum arabic.
The spiny branches serve as brushwood fence for the fields.