Juniperus procera
African Pencil Cedar
Family: Cupressaceae
Other Common Names: Ol tarakwa, Mtarakwa, Mwangati (Tanzania).
Distribution: East Africa; mainly in Kenya, Tanzania, and Uganda; found in the upland evergreen forests at elevations of 6,000 to 9,000 ft.
The Tree: Reaches a height of 100 to 120 ft; bole is tapered with a fluted base; trunk diameters mostly 4 to 5 ft but may reach 10 ft.
The Wood:
General Characteristics: Heartwood pale red, yellow brown, or purple red, becoming warm red brown on exposure; sapwood narrow, whitish, clearly differentiated. Texture fine; grain straight; quartersawn boards have an attractive figure; noticeable cedar scent. Spiral grain, ingrown bark, and compression wood are common.
Weight: Basic specific gravity (ovendry weight/green volume) about 0.48; air-dry density 36 pcf.
Mechanical Properties: (2-in. standard)
Moisture content Bending strength Modulus of elasticity Maximum crushing strength
(%) (Psi) (1,000 psi) (Psi)
Green (61) 11,100 1,280 5,800
Janka side hardness 765 lb for green material.
Drying and shrinkage: Dries moderately rapidly but in larger sizes tends to surface and end check. Kiln schedule T8-B3 is suggested for 4/4 stock and T5-B1 for 8/4. Shrinkage green to 12% moisture content: radial 2.0%; tangential 3.0%.
Working Properties: Works easily with hand and machine tools; being fissile it tends to break and chip in drilling and mortising; glues well, takes an excellent polish; liable to split in nailing.
Durability: Heartwood is classified as durable and resistant to most forms of insect attack.
Preservation: Heartwood is extremely resistant to impregnation; sapwood is permeable.
Uses: Slats for pencil manufacture, furniture, joinery, cabinetwork, tanks and vats shingles, millwork. Cedarwood oil is distilled from the sawdust.
Additional Reading: (3), (61), (67)