This very common species is noted for its occurrence as pure forest over large areas of country. It can be distinguished at a glance from _A. Sieberiana_, which it resembles in small trees, by its powdery orange or rust-coloured bark, or in the case of the variety _A. fistula_, by the colour being a milky white. It is generally a small tree from 15-30 feet in height, resembling _A. arabica_ in form, with an umbrella-shaped or flat-topped crown formed by the ascending and spreading branches. Sometimes the secondary branches are practically horizontal and the crown wide and quite flat on the top. It bears a profuse mass of bright yellow flower-balls, highly scented and very conspicuous. It occurs in clumps or isolated examples on stony ground, not in loose sand, but where the ground is broken up and barren looking. =The Bark=, the most distinguishing feature, is powdery and comes off in the hand with the appearance of minute flakes like bran. It is a rust-red or orange colour and in the case of the variety _A. fistula_ the bark is green with the powder milk-white in colour. A clear white or yellow gum exudes from the slash, which is light red and white, with brown edges. _A. fistula_ is light red with green edges. =The Thorns= are similar to those of _A. arabica_, but shorter, 1-2 inches long, white with black points, straight, strong and sharp and at an angle of about 100° to each other. The base is frequently largely swollen. Near the tips of the twigs little recurved thorns occur in place of the long, straight ones. =The Wood= is whitish, a brown colour being given it by the lines of hard tissue. It is apt to discolour with mould. In transverse section the close concentric rings of hard and soft tissue are very distinct, the pores are very numerous in the bands of soft tissue of varying width, the alternating bands of hard tissue being almost free of pores. The rays are straight, the larger plainly visible, the finer often closer together, showing as light-reflecting bands in radial section. In tangential section the hard tissue makes a well-defined grain of light brown. The wood is soft, the grain coarse; it works easily with tools, the plane giving a rough finish. Weight 50 lbs. a cubic foot. =The Leaves= are bipinnate, about 2 inches long with 6-8 pairs of pinnae cut up into some 15 pairs of leaflets. There are typically three in the angle of each pair of thorns and they are dark green when full grown. =The Flowers= are in yellow balls about ½ inch in diameter, 1-4 in the axil of a leaf. They have 1½ inch stalks, are sweet scented and appear from January onwards in masses which make the tree all yellow at a distance. The young leaves appear just as the flowers are going.