Branchlets subglabrous to crisped-pubescent.
Leaves 6–15 cm. long; stipules oblong or oblanceolate, sometimes slightly curved, bluntly pointed, 4–10 mm. long, often subpersistent; lateral leaflets 3–5 on either side of rhachis, ovate-lanceolate, ovate or elliptic, 2.5–6 cm. long, 1.2–3 cm. wide, acuminate, rounded at base, subglabrous or appressed pubescent particularly beneath; primary lateral nerves ± 7–10(–12) on either side of midrib.
Corolla 6.5–8 mm. long, white or cream, fragrant; standard elliptic-oblong to oblong-obovate, ± abruptly contracted to the well-developed claw, glabrous; wings practically as long as standard and shortly exceeding keel.
Stamens 9–10, all united or the vexillary stamen free.
Panicles on leafy shoots, lax, 4–10 cm. long, many-flowered; axes subglabrous to pubescent; bracts oblong-elliptic to spathulate, 1–3 mm. long, often somewhat persistent; bracteoles at top of slender 1.5–3 mm. long pedicel, rather smaller and narrower.
Calyx with the lateral lobes not or scarcely developed, thus 2-lipped, 4–5 mm. long, glabrous to thinly pubescent (particularly in Madagascar).
Fruit oblong-elliptic or oblong, narrowed at either end, with the short stipe 4.2–6.8 cm. long, 1.3–1.8 cm. wide, chartaceous, not much thickened over the seed-cavity but outer layer in this region darker coloured, becoming peripherally cracked and partially detached, dull brown, glabrous, very obscurely veined, 1–2-seeded.
Small tree or shrub, often scandent with aid of modified coiled branchlets from the older nodes, 3–7.5 m. tall; bark turning grey, striate, apparently not becoming very rough.
Calyx 4 mm long, deeply bilabiate, glabrous; upper teeth broad, shallow-lobed, the others very narrow, the lateral ones rather small ± hidden under the lower one which is c.2.5 mm long, acute.
Inflorescence of axillary and terminal panicles 3–8 cm long, very sparsely pilose, soon glabrous; bracts 1–1.5 mm long, bracteoles 1.5–3 mm long, caducous at anthesis.
Flowers white, scented, 5–6 mm long.
Young parts ± sparsely pilose, very soon becoming glabrous.
Leaves up to 12 cm long; petiole 1–2 cm long, rachis 4–8 cm long; petiolules 1.5–3 mm long; leaflets (2)3–5(6) on each side of the rachis, 1.8–5 × 1.5–3 cm, ovate to elliptic, acuminate-acute or blunt, sometimes emarginate at the apex, rounded at the base, sparsely appressed-pubescent beneath; lateral nerves in 3–5 pairs, these and the reticulation scarcely visible on either surface; stipules 3–8 mm long, subfalcate, caducous.
Climbing or scandent shrub or liane up to 6 m tall, occasionally with side branches on older wood becoming hooked or coiled and tendril-like, deciduous; branchlets reddish-brown, smooth or with sparse rather small lenticels.
Seed 6–8 × 4.5 × 2 mm; testa blackish-brown, glossy.
Pod flat, 1–2-seeded, 3.5–5.5 × 1.5 cm, thin and stiff to coriaceous, rounded or obtuse at the apex, cuneate at the base, smooth, yellowish-red over the seeds; stipe 3–4 mm long.
Ovary 3–4-ovulate, pilose on the midrib and suture; style 0.8 mm long; stipe c.3 mm long, puberulous.
Stamens connate in a single bundle.
Standard c.5 mm long, broadly obovate to subcircular, emarginate, subcordate at the base, claw c.2 mm long; wings as long as the standard, claw 2.5 mm long; keel petals somewhat shorter than the wings, free, slightly overlapping at the apex, claw 3 mm long.