Afzelia spp.

Afzelia

Family: Leguminosae

Other Common Names: Doussie (Cameroons), Apa, Aligna (Nigeria), Mkora, Mkola, Mbambakofi (Tanzania), Chanfuta, Mussacossa (Mozambique), Beyo, Meli, Azza (Uganda).

Distribution: West, Central, and East Africa. Occur in the dense evergreen forests but also common in the savanna and coastal forests of East Africa.

The Tree: Reaches best development on moist sites with heights of 80 to 120 ft and clear boles 30 to 50 ft; trunk diameters 3 to 5 ft and more; large irregular buttresses sometimes present.

The Wood:

General Characteristics: Heartwood reddish brown after exposure; sapwood pale straw to whitish, well defined. Texture moderate to coarse; grain straight to interlocked; medium luster; without characteristic odor or taste. Some pores contain a yellow dyestuff which, under moist conditions, can discolor textiles, paper, or other cellulosic materials.

Weight: Basic specific gravity (ovendry weight/green volume) 0.67; air-dry density 51 pcf.

Mechanical Properties: (2-cm standard)

Moisture content Bending strength Modulus of elasticity Maximum crushing strength

(%) (Psi) (1,000 psi) (Psi)

12% (40) 18,100 1,900 11,490

12% (56) 16,640 1,510 10,030

Janka side hardness 1,770-1,850 lb for dry material.

Drying and Shrinkage: Seasons satisfactorily but slowly with little or no degrade. Kiln schedule T6-D2 is suggested for 4/4 stock and T3-D1 for 8/4. Shrinkage green 12% moisture content: radial 1.0%; tangential 1.5%. Movement in service is rated as small.

Working Properties: Rather difficult to saw and machine because of rapid dulling of saw teeth and cutters but works to a smooth finish; some tearing of grain on radial faces. Difficult to stain where pores contain yellow deposits. Classified moderate in wood bending properties. Dust may be irritating. Difficult to glue.

Durability: Heartwood is rated as very durable and moderately resistant to termite attack; sapwood liable to attack by powderpost beetles. In East African waters, teredo are slow to attack and develop. Pholad attack is more rapid.

Preservation: Extremely resistant to preservative treatments; sapwood reported to be moderately resistant.

Uses: Exterior joinery (window frames, doors), flooring, heavy construction including harbor and dock work, furniture, because of good acid resistance used for vats and tanks.

Additional Reading: (3), (9), (40), (56)