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Albizia lebbeck (L.) Benth. |
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Leguminosae sometimes erroneously spelt Albizia lebbek or Albizzia lebbek |
Author:
Le Houérou
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Indian siris, acacia tree (Australia); mataratón (Colon, Panama); tibit tree, acacia (El Salvador). A small tree in the Sahel but may reach 20-30 m. in height in the humid tropics, with a high, deep seated crown, up to 28 m across and a relatively short bole. Bark flaky, pale grey, yellowish grey to greyish-violet with large, red to rust-brown, lenticels. Twigs dotted with white lenticels. Covered during the dry season with numerous pods light-grey to beige in color, rattling in the wind (woman's tongue) because of the free-moving seeds inside, hence identifiable from far-off. Leaves bipinnate with 2-4 pairs of pinnulae having 4-10 pairs of bright green leaflets, blunt at both ends, oblong-obovate, 2-5 cm long x 8-15 mm wide, petiole 3-5 cm with a large gland at the bottom, smaller glands on the underneath side of the rachis. Leaflets may be deciduous in the dry season. Flowers greenish-yellow to white, fragrant, in large globose heads, 2.5-7.5 cm in diameter, borne on a peduncle 5-10 cm long. Pods 10-30 cm long x 2-5 cm wide with 5-15 flat, rounded seeds, marcescent (remaining on the tree long after maturity). Tolerant to light frost. Suitable for the South Sahel on well watered soils (alternate phreatophyte), preferably black cotton soils, fairly tolerant to alkalinity and salinity. Originating in the Indian subcontinent, Burma and in the Cape York Peninsula in Australia. To-day cultivated in most tropical arid and semi-arid lands. In Barbados the deep root system makes it difficult to eradicate (Paterson, 1949). Propagation by seeds (8,000-10,000 / kg) or cuttings, or coppicing. Seeds are liable to attacks by weevils and other insects ; however, this may be prevented to some extent by early harvesting. Seed treatment by boiling water and subsequent soaking, as for acacias. Also, as for acacias, direct seeding is feasible under Sahel conditions as long as competition from weeds is prevented ; early growth is fast (1 m / year). The most important function in the Sahel is street and courtyard planting, and as shelter belts and shade trees. In the humid tropics the tree is used for shading cash-crops such as coffee and tea. Nitrogen fixation is very efficient. Due to its good ability for coppicing, A. lebbeck could be a substitute for Leucaena leucocephala and for Gliricidia sepium (Papilionoideae) as a fuel-and-fodder crop for semi-arid to sub-humid zones which are too dry and marginal for these species. The wood is used in cabinet making as a good veneer and carpentry (Indian walnut), and fuelwood ; foliage, twigs, flowers and immature pods are good browse; but mature pods are not palatable. Root fibers are used in wickerworks, the red gum produced is a substitute for gum arabic, the bark contains saponins and may be used as a substitute to soap. Flowers are attractive to bees and the honey therefrom is appreciated. The leaves are eaten when they fall. In the West Indies the tree is "pollarded" (the branches cut for fodder) and the pods are also used. Human medicine : flowers for boils, bark and seeds for diarrhoea, dysentery and haemorrhoids, seed oil for leprosy. Seedlings are liable to termite and rodent damage and should be protected against them ; the wood is attacked by various insects including termites. Aubréville 1950 ; Brenan 1957a ; Catinot 1967 ; Berhaut 1975 ; Giffard 1974a ; Kerharo & Adam 1974 ; Von Maydell 1983/86 ; Burkill 1995 ; Dommergues et al. 1999. |