| 1 | Pinnae 2 or 3 pairs, rachis and pinnae with numerous enlarged and raised lenticels |
| 1' | Pinnae 1 pair, rachis and pinnae without lenticels |
| 2 | Rachis- and pinna-glands with strongly raised margins |
| 2' | Rachis-and pinna-glands without raised margins, usually depressed or pit-like. |
| 3 | Leaflets glabrous or subglabrous beneath except perhaps for the patently hairy major veins |
| 3' | Leaflets densely pilose beneath, with an indumentum of short, patent hairs. |
| 4 | Inflorescence densely puberulous with patent hairs. Pod short and thick, oblong or ovate, sometimes divided into two short, thick, 1-seeded segments. Glands saucer- shaped |
| 4' | Inflorescence sparsely to densely puberulous with appressed hairs. Pod curved into a circle or a spiral. Glands not saucer-shaped |
| 5 | Inflorescence unbranched. Stipules c. 1 mm long, triangular, hard, caducous. Petiolules densely patently puberulous, principal lateral veins of leaflets with a rather dense patent pubescence beneath |
| 5' | Inflorescence branched. Stipules 4-8 mm long, filiform or subulate, sometimes rigid and persisting at the older leaves, but usually caducous. Petiolules puberulous; principal lateral veins of leaflets with minute appressed hairs only. |
| 6 | Rachis- and pinna-glands bowl-shaped |
| 6' | Rachis- and pinna-glands either circular with raised margins or hollow with a narrow orifice |
| 7 | Pinna-glands circular, 2 mm in diameter, sessile, with raised margins and a flat depressed central part; leaflets 7-17.5 by 2.5-6 cm, ovate-elliptic or oblong-lanceolate, base asymmetrically broadly cuneate. Calyx 1.5-2 mm long, glabrous. Corolla 7 mm long, glabrous. Pod unknown |
| 7' | Pinna-glands c. 2 mm in diameter, with raised margins and a narrow orifice; leaflets up to 25 by 10-16 cm, broadly ovate or elliptic, base rounded but blade often somewhat decurrent in the petiolule. Calyx 2-4 mm long, puberulous. Corolla 8-10 mm long, puberulous. Pod curved, fleshy or coriaceous, scarlet outside, yellow within, c. 21 by 7-10 cm |
| 8 | Inflorescence pubescent with greenish yellow patent hairs. Lower surface of leaflets faintly puberulous. Stipules unknown |
| 8' | Inflorescence glabrous or (densely) puberulous with appressed hairs. Lower surface of leaflets glabrous or faintly puberulous. Stipules persisting, or late caducous, linear-falcate |
| 9 | Inflorescences terminal. Rachis, pinnae and leaflets below minutely glandular hairy. Calyx 1-1.5 cm long, cupular. Pod contorted |
| 9' | Inflorescences cauliflorous, rarely at the upper leaf-axils. Rachis, pinnae and leaflets below glabrous to puberulous with eglandular hairs. Calyx 2.5-7 mm long, cupular to campanulate |
| 10 | Base of leaflets ± symmetrically cuneate or rounded. Pod curved into a semicircle, 7-17 cm long, 1.5-1.7 cm over the seeds, flattened with a slightly to strongly sinuate dorsal suture, sometimes moniliform due to abortion of some seeds |
| 10' | Base of leaflets symmetrically narrowly cuneate, decuirent in the petiolule. Pod 7-9 cm, basal part stalk-shaped, rugose, 2.5 cm long; upper part cylindrical, c. 3 cm wide, apparently indehiscent |
