BURKEA AFRICANA Hook. f.—Kolo, Kurdi, Bakin, makarfo, Namijin Kiriya, Kariye gatari. LEGUMINOSAE.
A fairly large tree up to 50 feet in height with girths of 3-6 feet. It is a fine upstanding tree, frequently with a 20 feet bole, straight and clean, with ascending branches and high crown, spreading with age. It bears a resemblance to Amblygonocarpus Schweinfurthii, from which it can be distinguished by its larger and unequal-shaped leaflets. It is plentiful in high savannah forests and will extend, by means of small hollows or valleys as far north as 12½°. In flower or seed it is readily distinguished, and the leafless tree can be recognised by the thick, blunt end of the branches, often tufted with the dead stalks of last year’s leaves.
The Bark is light grey with a bluish tint, and the scales are large and heavy, at times closely fitting, then falling in large sections, so that the trunk may appear shaggy. The branch bark, right up to the tips is very thick, with pronounced ridges and fissures and a light brown colour towards the ends. Often the leaf scars swell and form prominent knobs on the twigs. The slash is dark red and an oily resin exudes.
The Wood is reddish brown, the sapwood, light brown with an orange tinge. In transverse section the rings are very close, well-marked darker lines; the pores are very numerous, single and in festoons in well-developed soft tissue which shows up strongly in contrast with the hard tissue and nearly closes the pores. The rays are fine and evenly spaced, nearly straight, not visible to the naked eye owing to the amount of soft tissue. In vertical section the grain is close, the rings seen as bands of darker colour. The wood is very hard to saw and difficult to plane, but the planed surface is smooth and takes a high polish. It is liable to ring shake when seasoning, but is on the whole a sound, durable wood, very suitable for upright in constructional work. The weight is 72 lbs. a cubic foot.
The Leaves are some 18 inches long, at first erect, then drooping. They are bipinnate, with some four pairs of pinnae bearing 9-11 alternate leaflets, 1½-2 inches long and 1-1¼ inches broad, with unequal lobes and slightly cleft tip, bluish-green above, grey-green below, with a dull surface. The venation is prominent above and not beneath. The short leaflet stalk is curved.
The Flowers appear in March and April, mostly at the base of the new leaf shoot, a few only amongst the leaves higher up. They are in spikes or panicles up to 12 inches long, numerous, pendulous and conspicuous. The small white flowers are crowded and each consists of a minute calyx, 5 white petals which bend back in half, concealing the tips, 10 yellow-anthered stamens and a short blunt, curved pistil. The pentagonal shape of the corolla with its recurved petals and the erect stamens are noticeable. There is no scent.
The Fruits are pods, 2 inches long, 1 inch broad, thin, not flat, but tending to twist at the tip, forming a convex and concave side on the latter, of which the seed is clearly embossed. The colour is mahogany brown, veined, brittle and persistent. There is one brown, oval flat seed.
