The Flowers are very handsome “Pea-flowers” in small clusters on long stalks, branched, with a bract at each branch, springing from small clusters of bracts on the woody stems. The stalks are purple and hairy, the calyx is irregular, purple and green, and the corolla is a delicate pink with a pale green keel. The flowers are generally in great masses and a curious characteristic is that they dry up and retain almost their original shape, the pod ripening meanwhile.
The Fruits are small black jointed pods 1-1½ inches long with some 4-5 joints, oval, flattened and hairy, each containing one seed, pale brown in colour. The pod will often bend right round and its tip enter the mouth of the flower.
OSTRYODERRIS CHEVALIERI Dunn.—Durbi. LEGUMINOSAE.
A large tree some 40 feet or more high, common in some parts of Sokoto, Zaria and Katsina, but very local in its occurrence and extending as far north as 13°. The girth is up to 7 feet, more often 5 feet. It closely resembles Paradaniellia Oliveri in bark and leaf and form, especially in young trees of the latter species. The bole may be clean and straight for 20 feet and the crown is high and flat-topped in full grown trees. It does not grow on poor soils and its extension to 13° is by way of moister valleys and pockets of alluvial soil. The pods and flowers are the distinctive features.
The Bark is light grey with a strong resemblance to that of Paradaniellia Oliveri, the scales being even-sized, polygonal but not so large as those of P. Oliveri. Nor has it the red tinge of the latter. The slash is most distinctive, being a mixture of fibres of white, dark brown and crimson, like strands of wire.
The Wood is whitish or cream-coloured. In transverse section the rings are indistinct but the concentric lines of hard and soft tissue are well marked. The pores are single or in small groups, unequally scattered. The rays are invisible to the unaided eye, and waved slightly. In vertical section the pores are long and open, the hard and soft tissue well marked in parallel lines and the rays show as long, fine bands on the radial section. The wood is soft, medium weight, shows red streaks, is easily worked and the planed surface is smooth. It has a curious smell, The weight is 45 lbs. a cubic foot.
The Leaves are pinnate, 10-15 inches long with some 6 pairs and a terminal leaflet. The leaflets are opposite or nearly so and increase in size towards the top pair, the largest 3 inches long and 1½ broad, with cordate base, unequal lobes and an even taper to a rounded, cleft tip. The upper side is bluish-green with a bloom, the underneath pale grey-green. The venation is prominent beneath.
The Flowers, from February to April, are in erect panicles on the stout twig ends, some dozen or so on each twig. Each flower is white, papilionaceous, ¾ inch long. The calyx is covered with brown hairs, as are the flower-stalks and there is a green splash in the centre of the standard petal. The panicles are 6-8 inches long, gradually drooping.