Properties [ edit ]
|The heartwood is yellowish brown to reddish brown, with a golden or occasionally purplish shine, and distinctly demarcated from the 3–7 cm wide pale yellow to pinkish brown sapwood. The grain is interlocked, texture coarse. Radial surfaces show a nice figure.|
The wood is moderately heavy, with a density of 500–700(–820) kg/m³ at 12% moisture content. It dries slowly, but generally with little degrade. The rates of shrinkage are moderately low, from green to oven dry 2.2–3.5% radial and 4.6–5.4% tangential. Once dry, the wood is stable in service.
At 12% moisture content, the modulus of rupture is 65–114 N/mm², modulus of elasticity 9200–14,500 N/mm², compression parallel to grain 41–65 N/mm², shear 6–8.5 N/mm², cleavage 16–20.5 N/mm, Janka side hardness 3870–5600 N and Janka end hardness 4800–6760 N.
The wood generally saws and works easily with ordinary hand and machine tools, but the force required depends on the density. A small cutting angle is needed to avoid tearing. The use of a filler is recommended to obtain a good finish. The wood holds nails and screws well, but pre-boring is advised to prevent splitting. The gluing, steam-bending and veneering properties are all good. The wood dust may cause irritation to nose and throat.
The heartwood is durable. It is resistant to fungi and dry-wood borers, and usually also to termites, although wood from Liberia is reportedly liable to termite attack. The heartwood is resistant to impregnation with preservatives, the sapwood is permeable.
The bark from roots and bole contains high amounts of saponins, and the root bark also alkaloids. The content of protein in the leaves was 38%, and that of crude fibre 41%, both of which are comparatively high. In another test the crude protein content was only about 25%, while the leaves had a C/N ratio of 11.4, a lignin/N ratio of 10.3 and a polyphenol/N ratio of 0.82, indicating that the leaf litter is slow to decompose.
Sort by: content a-z source
|Large deciduous tree up to 45(–50) m tall; bole branchless for up to 22(–30) m, straight and cylindrical, up to 100(–130) cm in diameter, without buttresses or sometimes with small, thick buttresses up to 1.5 m high; bark yellowish brown to dark grey, rough and scaly, inner bark fibrous, yellowish to orange-brown, with darker stripes and clear or honey-coloured gum; crown dome-shaped, heavily branched, with fairly spreading branches; young branches densely rusty hairy. Leaves alternate, bipinnately compound with 3–7 pairs of pinnae; stipules awl-shaped, caducous; petiole (2–)3–4.5(–6) cm long, at the middle of upper side with a sessile gland, rachis (2–)4–15 cm long, rusty hairy; leaflets in 6–14(–20) pairs per pinna, sessile, elliptical to oblong, slightly oblique, 1–2.5 cm × 0.5–1 cm, rounded at apex, densely pubescent below. Inflorescence an axillary head on (2–)5–10 cm long peduncle. Flowers bisexual, regular, 5-merous, white to yellow, subtended by up to 7 mm long bracteoles; pedicel up to 3 mm long; calyx 3–6 mm long, with long tube and short lobes, densely rusty pubescent outside; corolla 9–13 mm long, with c. 6 mm long tube, rusty pubescent outside; stamens numerous, 3–5.5 cm long, united into a tube in lower half; ovary superior, c. 3 mm long, gradually tapering into an up to 3 cm long style. Fruit an oblong, flat pod 15–24 cm × 3–5 cm, glabrous, transversely veined, yellowish brown when ripe, opening with 2 papery valves, c. 10-seeded. Seeds flattened globose to ellipsoid, 7–10 mm × 4.5–8 mm. Seedling with epigeal germination; hypocotyl 4–6 cm long, epicotyl 1–2.5 cm long; cotyledons c. 1 cm long, thick and fleshy, rounded, early caducous; first 2 leaves opposite, one pinnately compound and the other bipinnately compound.|
Sort by: content a-z source
|Albizia comprises about 120 species and occurs throughout the tropics. Approximately 35 species are found in continental Africa and about 30 in Madagascar. It is characterized by the head-like inflorescence, with 1–2 central flowers modified, functionally male and having a larger, nectar-producing staminal tube. Molecular analyses showed that Albizia is heterogeneous, and a revision of the genus is needed.|
Albizia coriaria Welw. ex Oliv. closely resembles Albizia ferruginea. It differs in its less densely hairy leaves and flowers, and in its stamen filaments being red above (whitish or greenish in Albizia ferruginea). The two species are much confused in the literature, and used for similar purposes, as timber, firewood, charcoal, ornamental, forage and medicinal plant. Albizia coriaria is a smaller tree, rarely up to 35 m tall, and occurs from Côte d’Ivoire eastwards to Ethiopia and Kenya, and south to eastern Tanzania, Zambia and northern Angola. In West Africa Albizia coriaria occurs particularly in the transition zone between savanna and dry forest, whereas Albizia ferruginea is more characteristic for semi-deciduous forest. In East Africa the former occurs in wooded grassland and riverine forest at 850–1700 m altitude, the latter in lowland rainforest at 800–1200 m altitude.
Albizia malacophylla (A.Rich.) Walp. may be confused with Albizia ferruginea, but it is a small tree up to 15 m tall, with grey to whitish hairs on the calyx. It occurs from Senegal to Uganda in wooded savanna and dry forest, and its wood is used to make pestles and as firewood. Its gum is used to mend broken pottery, its foliage is browsed by camels, and its roots are used to treat conjunctivis and backache.
Albizia tanganyicensis Baker f. (paperbark albizia) also shows some resemblance to Albizia ferruginea, but it differs in its peeling, brownish red, papery bark revealing the creamy young bark, its broader leaflets, its flowers usually produced before the new leaves, and its thicker pod valves. It is a small to medium-sized tree up to 20 m tall of deciduous woodland from Kenya and Tanzania south to Mozambique and South Africa and from there west to Angola. Its light and whitish wood is occasionally used, e.g. for carving. Root powder is rubbed into scarifications to treat swollen legs and is used as a tonic. A root infusion is drunk against impotence and a bark decoction to treat cough. Pods and seeds of Albizia tanganyicensis are poisonous to livestock; young pods are most toxic.
Sort by: content a-z source
|Wood-anatomical description (IAWA hardwood codes):|
Growth rings: (1: growth ring boundaries distinct); (2: growth ring boundaries indistinct or absent). Vessels: 5: wood diffuse-porous; 13: simple perforation plates; 22: intervessel pits alternate; (23: shape of alternate pits polygonal); 26: intervessel pits medium (7–10 μm); 29: vestured pits; 30: vessel-ray pits with distinct borders; similar to intervessel pits in size and shape throughout the ray cell; 43: mean tangential diameter of vessel lumina 200 μm; 46: 5 vessels per square millimetre; (47: 5–20 vessels per square millimetre); 58: gums and other deposits in heartwood vessels. Tracheids and fibres: 61: fibres with simple to minutely bordered pits; 65: septate fibres present; 69: fibres thin- to thick-walled. Axial parenchyma: 79: axial parenchyma vasicentric; 80: axial parenchyma aliform; 81: axial parenchyma lozenge-aliform; 83: axial parenchyma confluent; 91: two cells per parenchyma strand; 92: four (3–4) cells per parenchyma strand. Rays: (97: ray width 1–3 cells); (98: larger rays commonly 4- to 10-seriate); 104: all ray cells procumbent; 115: 4–12 rays per mm. Mineral inclusions: 136: prismatic crystals present; 142: prismatic crystals in chambered axial parenchyma cells.
(P. Ng’andwe, H. Beeckman & P.E. Gasson)
Sort by: content a-z source
|In exposed sites, seedlings may grow up to 3 m tall in 5 years. In Ghana seedlings reached a height of 2 m within 2 years. In a selection test for agroforestry species on acid, aluminium toxic soils in southern Cameroon, seedlings reached a height of hardly 2 m in 20 months, which was less than 20% of the height of the best performing species (Inga edulis Mart. and Pterocarpus santalinoides L’Hér. ex DC.). The roots develop nitrogen-fixing nodules. Albizia ferruginea is highly dependent on arbuscular mycorrhizae. The leaves show sleep movements at night. Leaves fall after the rainy season, and new flushes are red. In Liberia trees flower in February and March, and the fruits ripen in December to February. The fruits dehisce on the tree and the papery valves with seeds still attached are spread by wind.|
- Джабба засопел и сделал изрядный глоток. - Если бы в игрушке Стратмора завелся вирус, он бы сразу мне позвонил. Стратмор человек умный, но о вирусах понятия не имеет. У него в голове ничего, кроме ТРАНСТЕКСТА.