Microscopy: Technical Information Sheet

DALBERGIA RETUSA

Cocobolo Dalbergia retusa Hemsl. Leguminosae (Papilionoideae)

The genus Dalbergia contains about 300 species, from the tropical and sub-tropical regions of the world (Asia, Africa, Central America & South America) as well as South Africa. The word Dalbergia is in dedication to N. Dalberg (1735-1820), a Swedish physician. The valuable timber species are:

Scientific Name Trade Name Native To
D. cearensis Kingwood Brazil
D. cochinchinensis Trac Southeast Asia
D. decipularis Sebastiao de Arruda Brazil
D. frutescens Tulipwood South America
D. granadillo Granadillo Mexico
D. latifolia Indian Rosewood India
D. melanoxylon African Blackwood Africa
D. nigra Brazilian Rosewood Brazil
D. oliveri Burma Tulipwood Southeast Asia
D. retusa Cocobolo Panama
D. sissoo Sissoo India
D. spruceana Amazon Rosewood South America
D. stevensonii Honduras Rosewood Honduras

Distribution: Pacific regions of Central America and extending from Panama to southwestern Mexico. Of limited occurrence, usually in the drier uplands.

Other Common Names: Black rosewood, cocobola, cocobolo, cocobolo nambar, cocobolo negro, cocobolo prieto, cocoboloholz, foseholz, funera, granadillo, granadillo de chontales, manarizoby, namba, nambar, nambar de agui, nambar legitimo, Nicaraguan cocobolo, Nicaraguan rosewood, nambar, palisandro, palissandre cocobolo, palo negro, prieto, red foxwood, rosewood, yellow rosewood.

The Tree: A small to medium-sized tree 45 to 60 ft high with trunk diameters of 20 to 24 in.; usually of poor form.

The Wood: Like many other woods of this family, cocobolo possesses to a very high degree, the valuable characteristics of density, color and durability. Somewhat variable in color when freshly sawn, with the heartwood becoming a light reddish-orange to a deep rich red or rose, beautifully marked with numerous, irregular, concentric markings of deep or black purple.

Cocobolo has a fine texture with straight to interlocked grain. It has an oily feel, no distinctive taste and a slightly pungent and fragrant odor when worked. It has a basic specific gravity (ovendry weight/green volume) of 0.80 to 0.98 and an air- dry density of 62 to 76 pounds per cubic foot. It is strong, hard, compact and fairly heavy, easily worked, of extreme durability and is naturally in high favor with the cutlery and turnery trade. It is denser and stronger than Brazilian rosewood (Dalbergia nigra). It is reported to have excellent drying properties and is free of surface and end checking. Its shrinkage is usually low with high stability in use and very low moisture absorption. It is reported to have excellent machining characteristics. It possesses natural oils which give the wood a good polish, but make it unsuitable for gluing. The oils also tend to waterproof it and make it resistant to the influence of moisture, even when left in contact with water indefinitely. It is this latter characteristic which is mainly responsible for the supreme position that cocobolo holds in the cutlery trade.

Durability: Durability is high, and has a very high resistance to marine borer attack.

Uses: Highly favored in the cutlery trade for handles, inlay work, brush backs and small tool handles, musical and scientific instruments, jewelry boxes, chessmen, butts of billiard cues, and other specialty items.

Toxicity: Can cause contact dermatitis from sand-papering of cocobolo hairbrushes; localized dermatitis from contact with knife-handles, bracelets, recorders and other finished articles made of cocobolo wood; nasal irritation in workers finishing and sanding cocobolo wood. The allergenic chemicals are S-4'-hydroxy-4-methoxy dalbergione, R-4-methoxy dalbergione and other quinones and phenols.

Additional Reading:

Boutelje, J. B. Encyclopedia of world timbers, names and technical literature. Stockholm, Sweden: Swedish Forest Products Research Laboratory; 1980.

Chudnoff, M. Tropical timbers of the world. Ag. Handbook #607. Washington: USGPO; 1984.

Hausen, B. M. Woods injurious to human health. A manual. New York, NY: Walter de Gruyter; 1981.

Mitchell, J. and Rook, A. Botanical Dermatology: Plants and Plant Products Injurious to the Skin. Vancouver: Greengrass Ltd.; 1979.

Record, S. J. and Garratt, G. A. Cocobolo. New Haven, CT, USA: Yale University Press, Yale University, School of Forestry, Bulletin No. 8; 1923.

Record, S. J. and Hess, R. W. Timbers of the New World. New Haven: Yale University Press; 1943.

Terrell, E. E. and Terrell, E. E. A checklist of names for 3,000 vascular plants of economic importance. Washington, DC: USDA, Ag Handbook No. 505; 1986.

Woods, B. and Calnan, C. D. British Journal of Dermatology, Toxic Woods. Great Britain: Alden Press; 1976.