Other Common Names: Okuro (Ghana), Ayinre, Uwowe (Nigeria), Mugavu, Nongo (Uganda), Mtanga, Mduruasi (Tanzania).
Distribution: Widely distributed throughout tropical Africa; mostly trees of the high forest are exploited, but also common in secondary forests.
The Tree: May reach heights of 120 to 150 ft with trunk diameters of 3 ft; some species with a total height of 60 ft and a diameter of 1.5 to 2.0 ft; sometimes buttressed; boles tend to be irregular in dry areas.
General Characteristics: Heartwood golden yellow, light brown, red brown, or dark brown, sometimes with a greenish, purple, or red tinge, sometimes with dark streaks sapwood whitish, yellowish, or pinkish brown, well demarcated. Texture variable from fine to coarse; grain straight to interlocked or irregular and wavy; may have a silky sheen; without characteristic odor or taste. Dust may irritate mucous membranes.
Weight: Basic specific gravity (ovendry weight/green volume) 0.45 to 0.59; air- dry density 35 to 45 pcf.
Mechanical Properties: (First set of data based on the 2-cm standard, second and third sets on the 2-in. standard.)
Moisture content Bending strength Modulus of elasticity Maximum crushing strength
(%) (Psi) (1,000 psi) (Psi)
Green (57) 7,235 850 4,300
12% 8,855 1,060 6,420
15% (66) 12,000 1,480 6,000
12% (4) 12,310 1,640 6,140
Janka side hardness 750 to 1,160 lb for dry material.
Drying and Shrinkage: Seasons slowly and with little or no degrade. Kiln schedule T6-D4 is suggested for 4/4 stock and T3-D3 for 8/4 (West African species). Shrinkage green to ovendry: radial 2.4%; tangential 3.8%. Movement in service is rated as small.
Working Properties: Saws and machines well and works easily with hand tools and dresses smoothly but with some tearing of interlocked grain; glues well. Intense irritation may be caused by the sawdust.
Durability: Heartwood moderately durable but generally vulnerable to termite attack.
Preservation: Heartwood impermeable to preservatives; sapwood is treatable.
Uses: Furniture, joinery, flooring.
Additional Reading: (3), (4), (57), (66)
3. Bolza, E., and W. G. Keating. 1972. African timbers-the properties, uses, and characteristics of 700 species. CSIRO. Div. of Build. Res., Melbourne, Australia.
4. Bryce, J. M. 1966. The strength properties of Tanzania timbers. Util. Sec. For. Div. Tec. Note No. 35.
57. Tanzania: Util. Div. For. Dep. 1966. Timbers of Tanganyika: Albizia versicolor. Moshi.
66. Uganda: For. Dep. 1972. (Albizia coraria). Util. Sec. For. Dep. Timb. Leafl. No. 48.
From: Chudnoff, Martin. 1984. Tropical Timbers of the World. USDA Forest Service. Ag. Handbook No. 607.