USDA Forest Service
Forest Products Laboratory
One Gifford Pinchot Drive
Madison, WI 53705-2398
Wood Technical Fact Sheet
Other Common Names: Muhumula, Musira (Tanzania), Muhongera, Muguruka (Uganda), Muhunya (Kenya), Manasati (Ivory Coast).
Distribution: Occurs in Western, Central, and Eastern Africa along the equator. Typically a forest-edge species. Plantations have been established in Zaire and Uganda.
The Tree: Usually 90 to 120 ft high, bole straight and cylindrical, clear to60 ft; buttressed or root swellings short and blunt; trunk diameters 4 to 6 ft. Size of tree decreases across Africa from east to west. In Nigeria trees are seldom over 50 ft in height.
General Characteristics: Heartwood bright yellow green or green brown turning to a golden brown on exposure; sapwood nearly white, wide, clearly demarcated. Grain typically interlocked producing a ribbon figure; texture medium to coarse; without characteristic odor or taste when dry. Pin knots sometimes present, rather knotty near the core.
Weight: Basic specific gravity (ovendry weight/green volume) 0.41 (plantation- grown material 0.35); air-dry density 30 pcf.
Mechanical Properties: (First set of data based on the 2-cm standard; second set on the 2-in. standard.)
Moisture content Bending strength Modulus of elasticity Maximum crushing strength
(%) (Psi) (1,000 psi) (Psi)
Green (9) 8,000 1,170 4,140
12% 11,000 1,340 6,670
Green (5) 5,400 950 3,020
12% 8,200 1,140 5,000
Janka side hardness 460 to 680 lb for green material and 500 to 700 lb for dry.
Drying and Shrinkage: Dries fairly rapidly with some warp but no surface or end checking. Logs may split full length, though, in felling and storage. Kiln schedule T6-D4 is suggested for 4/4 stock and T3-D3 for 8/4. Shrinkage green to 12% moisture content: radial 2.5%; tangential 4.0%. Movement in service is rated as small.
Working Properties: Saws and machines very easily and works well with hand tools; planes to a smooth finish if knives are kept sharp; must be supported when drilling and mortising; good gluing and nailing characteristics; difficult to finish because of high absorbency.
Durability: Heartwood readily attacked by decay fungi and termites.
Preservation: Heartwood and sapwood generally rated as permeable.
Uses: Light construction, boxes and crates, millwork, plywood or core stock. Value as a softwood substitute. The bark is used in the Congo region as a roofing material.
Additional Reading: (3), (5), (8), (9)