Standard yellow, usually streaked or with dark purple speckles, 2.2–2.7 × 1.7–2.2 cm, broad, rounded, apically emarginate, the appendages with blunt strongly incurved free tips up to 1.5 mm long; wings yellow, 2.2–2.6 cm × 5–8 mm, with an acute basal tooth variable in length or without an obvious tooth, and with lamellate sculpturing in the upper basal one-third to one-half on the outer face; keel yellowish-green, 2.2 cm × 6–11 mm, with a broad subquadrate limb and a basal tooth projecting upwards.
Leaves 7–36 cm long; petioles 0.3–1.2(4.5) cm long; leaflets in 20–65 pairs, 0.6–3.5 cm × 1.5–6.5 mm, oblong, obtuse or rarely emarginate at the apex, apiculate, glabrous or sparsely spreading pubescent especially on the midvein and margins beneath; stipules up to 7 mm long, marginally or totally woolly, caducous.
Raceme 7–33 cm long, 13–23(26)-flowered; peduncle (1)2–7.5 cm long, densely woolly to sparingly pubescent or glabrescent; pedicels 1–2.2 cm long, densely pubescent, glabrescent or glabrous; bracts caducous; bracteoles 2.5–3 mm long, linear-lanceolate, marginally pubescent to glabrous, caducous.
Seeds olive-green, brown or black, sometimes mottled, 3.5–5 × 1.5–2 mm, 1.5–2 mm thick, subcylindrical; hilum in a subcentral circular pit surrounded by an obscure rim aril.
Calyx 6.5–9 × 6–9 mm, oblique, the tube glabrous or sparsely pubescent, the teeth 0.75–1 mm long, acuminate, slightly pubescent marginally.
Stems pithy, glabrous, glabrescent or less commonly densely shortly woolly, particularly on the young branches.
Seedlings with first foliage leaf simple, ± equalling the cotyledons in size, second foliage leaf paripinnate.
Ovary glabrous or rarely pubescent on the lower suture; style glabrous.
Short-lived suffrutescent perennial herb 2.5–4 m tall.