TCHITOLA

Tchitola

Oxystigma oxyphyllum

Family: Leguminosae

Other Common Names: Lolagbola (Nigeria), M'Babou (Gabon), Tshibudimbu (Zaire), Tola mafuta (Angola).

Distribution: Occurs in tropical West Africa from Nigeria to Gabon and the Congo region; usually in dense mixed formations along rivers and lakeshores.

The Tree: Up to 150 ft in height; bole straight and cylindrical, clear to 70 ft, unbuttressed; trunk diameter 2 to 3 ft, sometimes to 6 ft.

The Wood:

General Characteristics: Heartwood reddish brown with dark gum rings, suggesting walnut; sapwood 4 to 5 in. wide, light yellow pink, distinct. Texture variable from fine to moderately coarse; grain straight or shallowly interlocked; a gummy wood.

Weight: Basic specific gravity (ovendry weight/green volume) 0.53; air-dry density 40 pcf.

Mechanical Properties: (2-cm standard)

Moisture content Bending strength Modulus of elasticity Maximum crushing strength

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

Green (40) 11,700 1,520 5,700

12% 16,200 1,680 8,300

12% (44) 15,000 1,350 8,100

Janka side hardness: 1,100 lb for green and 1,250 lb for dry material. Amsler toughness 188 in.-lb at 12% moisture content (2-cm specimen).

Drying and Shrinkage: Seasons well with little checking or warp. A kiln schedule similar to T5-02 has been suggested. Shrinkage green to ovendry: radial 5.1%; tangential 10.7%. Reported to have a small movement in service.

Working Properties: Saws easily and works well with hand and machine tools, presence of gum may clog the cutters, nails and glues well, peels and slices well, takes a satisfactory finish.

Durability: Heartwood durability variable, generally moderately resistant, not very susceptible to termite attack. Logs, however, must be removed from the forest soon after felling to avoid degrade due to insect and fungal attack. Sapwood liable to powder-post beetle attack.

Preservation: Reported as probably permeable to preservative treatments.

Uses: Decorative veneers, furniture and cabinetwork, joinery.