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


Wood Technical Fact Sheet


 Gonioma kamassi


Family: Apocynaceae

Other Common Names: Cape boxwood, Kamassihout, Knysna boxwood, Kamassi boxwood (South Africa).

Distribution: Confined mainly to the midland coastal districts of South Africa.

The Tree: Usually about 20 ft in height; bole seldom over 10 ft in length; trunk diameter about 1 ft.

The Wood:

General Characteristics: Wood a uniform yellow or yellow brown, heartwood and sapwood not clearly defined. Texture exceptionally fine and even; grain straight, no figure; odor is lacking, but with a bitter taste. Fine dust may cause headaches, giddiness, skin inflammation, and asthma.

Weight: Basic specific gravity (ovendry weight/green volume) 0.75; air-dry density 58 pcf.

Mechanical Properties: (2-in. standard)

Moisture content Bending strength Modulus of elasticity Maximum crushing strength

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

12% (1) 20,970 2,543 10,530

Janka side hardness 2,730 lb at 12% moisture content.

Drying and Shrinkage: Seasons well if dried slowly, otherwise surface and end-checking can be severe. Kiln schedule T3-C2 is suggested for 4/4 stock and T3-C1 for 8/4. Shrinkages are reported to be high.

Working Properties: Sawing satisfactory with only a moderate blunting effect, not too difficult to work with hand tools, works to an excellent finish in most operations, turns exceptionally well.

Durability: Reported to be durable in ground contact but also reported to be liable to staining.

Preservation: Extremely resistant to impregnation.

Uses: Precision instruments, fancy turnery, engravers' work, shuttles, small tool handles.

Additional Reading: (1), (3), (9)