Tree up to 8 m. tall; all young parts other than corolla densely brown pubescent, except the leaflets, which are grey. Stipules oblong, up to 20 by 5 mm.; leaf-rhachis up to 26 cm., including a petiole of up to 9 cm., prolonged up to 2.5 cm. beyond lateral leaflets; stipellae subulate, 3–5 mm.; petiolules 6–7 mm. long; leaflets 7–9, elliptic-oblong, up to 17 by 10 cm., slightly cordate, with a very short triangular-acuminate tip, finally glabrescent above; main nerves 8–12 on each side, reaching or just failing to reach the margin; vein-network prominent on both surfaces. Pseudoraceme terminal, up to 40 cm. long, the floriferous branches up to 3 cm. long with numerous flowers throughout their length, the bracts at their base oblong, spurred, up to 11 by 3 mm.; pedicels up to 14 mm. long; bracteoles ovate, 1–3 mm. long, very caducous. Calyx-tube 8 mm. long; lobes triangular, obtuse, 2–3 mm. long, the upper pair united to 0.3 mm. from the tip. Corolla mauve; blade of standard whitish silky outside, with 2 shelf-like transverse folds at the base, not auriculate, ± 24 mm. long by 20 mm. wide; claw abruptly widened at the middle, 6 mm. long; wings pubescent at tip only; blade 22 mm. long by 4–7 mm. wide, with an auricle 3 mm. long; claw 7 mm.; keel glabrous. Vexillary stamen curved and free below, adhering above; filament-sheath 18–20 mm., free parts 6–7 mm., anthers 1.6 mm. long. Disc of 10 fleshy lobes, pubescent. Ovary 8 mm. long, with a stipe of 1–2 mm., densely pubescent, 6-ovulate; style 16 mm. long, pubescent for 10 mm., then bent sharply through 100°, glabrous above, straight at the tip; stigma globular. Pod suboblong, 14–15 cm. long by 3–3.5 cm. wide, brown, velvety, 4–6-seeded. Seeds transverse, elliptic-oblong, the hilum terminal; funicle not, or hardly, dilated.