Family: Fabaceae or Leguminosae, the legume family; the pea group.
Origin: It has a rather extensive range in the savanna regions from Sudan south to Mozambique, west to Angola and north to Nigeria and Senegal. It is the national tree of Tanzania.
Other Common Names: Congowood, mufunjo, mpingo, mugembe, babanus, mukelte, grenadilla, Mozambique ebony and Cape Damson ebony.
The Tree: African blackwood is a relatively small tree, multi-stemmed and much branched, usually growing from 15 to 25 ft. tall but my reach heights of 50 ft. in ideal conditions. The bole is short, often fluted, seldom cylindrical and rarely over 1 ft. in diameter with smooth gray bark that peels in strips when mature. It has compound leaves with alternating leaflets and it has thin, oblong pods holding 1 to 2 seeds.
Appearance: The heartwood is dark purplish-brown with predominate black streaks so that the general effect is nearly black and is very clearly demarcated from the yellow or white sapwood. The grain is straight with a fine and even texture and a low luster. It is slightly oily.
Density: African blackwood is very hard and heavy. Average reported specific gravity is 1.08(ovendry weight/green volume), equal to an air-dried weight of 91 pcf. Janka hardness is 4050 pounds of force.
Drying and Shrinkage: Timber must be seasoned very slowly and tends to split so end coating of the logs or billets is necessary. Drying times of 2 to 3 years are common. Movement in service is rated as small. Average reported shrinkage value (green to ovendry) is 7.6% volumetric.
Working Properties: It has exceptionally good working qualities. It cuts very smoothly and evenly although saw teeth dull rapidly. It is readily worked to a smooth, lustrous finish. It holds screws well but has to be drilled and tapped first. Possible adverse reactions from the dust include acute dermatitis, conjunctivitis, sneezing and asthma.
Durability: The heartwood is highly durable, moderately resistant to termites and is sometimes attacked by borers in standing trees. The sapwood is susceptible to attack by powder-post beetles.
Uses: African blackwood is used primarily for the manufacture of woodwind instruments, but is also used for other turnery work, brush backs, knife handles, walking sticks, inlay work, chessmen, carvings and many other small specialty items.
Availability: The timber is exported from East African ports in the form of small logs 3 to 5 ft. in length and is priced by the pound. It is considered expensive.