Brachystegia eurycoma

Brachystegia eurycoma, a plant in the family Fabaceae, is a sizable species of tree found in southern Nigeria and western Cameroon. It has a spreading, flattened crown.

Description
A fairly large tree, B. eurycoma reaches a height of about 35 m and a diameter of 2.5 m. The trunk is irregular, with small buttresses. The outer bark is rough, brownish-grey, and peels away in large flakes. The inner bark is red and fibrous, darkening on exposure to the air and exuding a yellowish or reddish gum. The crown is broad and flattened, the branches are spreading and irregular and the twigs are downy when young. The leaves are pinnate with a short petiole swollen at its base and four to six pairs of oblong-elliptical leaflets, the basal ones being the smallest and the terminal ones the largest. The inflorescence is a terminal panicle, the individual flowers having short stalks and being surrounded by dense brown hairs; the flowers are petal-less and have a boss of ten long stamens and a long coiled pistil. The fruits are flattened pods and the glossy brown seeds are disc-shaped and about 2 cm in diameter; when ripe, the pods burst explosively and throw out the seeds.

Distribution and habitat
Brachystegia eurycoma is endemic to southern Nigeria and western Cameroon, and possibly to Gabon. It is a fairly common tree in riverine forests. It is found in miombo woodland at altitudes of up to about 1150 m.

Human uses
Timber from this tree is used locally but is not exported; the heartwood is hard and difficult to work, and the wood is liable to split unless dried with care. The seeds are ground into a flour, known as achi, which can be used as a thickening agent, and the active ingredient, a polysaccharide, has been investigated as a wound-healing agent when mixed with snail mucin. The gum is used in a similar way to gutta-percha. Extracts from the wood have some anti-fungal and anti-termite properties.