USDA Forest Service
Forest Products Laboratory
One Gifford Pinchot Drive
Madison, WI 53705-2398
(608) 231-9200

 

Wood Technical Fact Sheet

 

 Tarrietia utilis

and T. densiflora

Niangon

Family: Sterculiaceae

Other Common Names: Nyankom (Ghana), Ogoue (Cameroon), De-orh (Liberia), Yawe (Sierra Leone).

Distribution: West Africa from Sierra Leone to Ghana (T. utilis), Cameroon and Gabon (T. densiflora). Found in the lowlands as well as hilly areas.

The Tree: May reach a height of 100 to 130 ft; bole usually straight and clear to 65 ft, sometimes irregular; trunk diameter 2 to 3 ft, buttressed, frequently stilt rooted in swampy areas.

The Wood:

General Characteristics: Heartwood pale pink- to red brown, darkening on exposure; sapwood up to 3 in. wide, whitish, not always clearly demarcated. Grain generally interlocked, sometimes wavy; texture somewhat coarse; luster medium to low; greasy feel; figured on radial surfaces due to high wood rays.

Weight: Basic specific gravity (ovendry weight/green volume) T. utilis 0.54, T. densiflora 0.63; air-dry density respectively 39 and 48 pcf.

Mechanical Properties: (2-cm standard)

Moisture content Bending strength Modulus of elasticity Maximum crushing strength

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

Green (9) 10,200 1,220 5,300

12% 13,000 1,380 7,500

12% (45) 17,600 1,830 8,500

Janka side hardness 1,050 lb for green material and 1,100 lb for dry. Amsler toughness 236 in.-lb at 12% moisture content (2-cm specimen).

Drying and Shrinkage: Dries fairly rapidly and well (T densiflora seasons slowly) sometimes with a tendency to twist. Kiln schedule T6-D2 is suggested for 4/4 stock and T3-D1 for 8/4. Shrinkage green to 12% moisture content: radial 2.5%; tangential 4.5%. Movement in service is rated as medium.

Working Properties: Works rather easily with hand and machine tools with only moderate blunting, a cutting angle of 15 degrees is suggested when planing to prevent tearing, excess gum may cause finishing problems, good gluing properties.

Durability: Heartwood is rated as durable; sapwood liable to powder-post beetle attack.

Preservation: Heartwood is extremely resistant; sapwood resistant.

Uses: Furniture components, carpentry and joinery, boatbuilding, greenhouses.

Additional Reading: (3), (9), (45)