| 1 | Infructescences cauline (inflorescence unknown). Leaves 1-foliolate. Pods densely pubescent, 2- or 3-seeded |
| 1' | Inflorescences and/or infructescences axillary and/or terminal |
| 2 | Leaflets entirely glabrous on the lower surface |
| 2' | Leaflets velutinous-hirsute to minutely apressedly puberulous (at least on the midrib and nerves), rarely glabrescent and seemingly glabrous, on the lower surface |
| 3 | Stipules falcate, or foliaceous, 5-9 mm long |
| 3' | Stipules ovate, very small or minute, up to 3.5 mm long |
| 4 | Stipules connate at the base, 5-6 mm long. Leaves (l-)2-3(-4)-foliolate. Bracts at the base of peduncles usually subulate, up to 8 mm long, sometimes aggregate, surrounding the base and brush-like |
| 4' | Stipules free, 7.5-9 mm long. Bracts at the base of peduncles ovate, c. 3 mm long, not as above |
| 5 | Stipules up to 7.5 mm long. Leaves (4-)5-6-foliolate. Pods obliquely obovate, 11 by 5-6 cm, puberulous |
| 5' | Stipules 9 mm long. Leaves 4- or 5-foliolate. Pods elliptic to elliptic-obovate, up to 15 by 6-7 cm, brown velvety |
| 6 | Leaves 1- or 2-foliolate |
| 6' | Leaves 3- or 4-foliolate, rarely associated with some 1- or 2-foliolate ones (in C. gracilis) |
| 7 | Leaves usually 1-foliolate, when 2-foliolate then leaflets often not opposite. Ovary 3- or 4-ovuled |
| 7' | Leaves usually with 2 opposite leaflets, sometimes 1-foliolate. Ovary 2-ovuled. |
| 8 | Pedicels long, (7-)15-22(-30) mm. Calyx lobes usually puberulous on the central, longitudinal part inside. Pods shining |
| 8' | Pedicels very short, 0-2 mm. Calyx lobes glabrous inside |
| 9 | Inflorescences erect, up to c. 5 cm long, rachis scurfy-velvety. Calyx lobes velvety outside. Ovary 6-ovuled |
| 9' | Inflorescences pendulous, longer, 8-30 cm long, rachis glabrous. Calyx lobes glabrous outside |
| 10 | Leaves (l-)3-foliolate. Stamens 8 or 9 |
| 10' | Leaves 4-foliolate. Stamens 5 |
| 11 | Bracts usually lanceolate to linear, 7-15 mm long. Bracteoles 6-9 mm long. |
| 11' | Bracts and bracteoles, if present, usually very small, less than 5 mm long.. |
| 12 | Pedicels 6-15 mm, articulated at the apex; bracteoles 2, opposite, at the apex of the pedicel. Pods velvety |
| 12' | Pedicels 15-20 mm, articulated at the base; bracteoles 2, subopposite or alternate, at the upper half of the pedicel. Pods shortly hairy |
| 13 | Leaflets rotund or apiculate at the apex. Leaves (1- or) 2-foliolate. Pods brownish hairy |
| 13' | Leaflets often acuminate, caudate, or cuspidate at the apex |
| 14 | Leaves usually 2- or 3-foliolate |
| 14' | Leaves usually more than 3-, up to 13-foliolate |
| 15 | Stipules free. Inflorescences very short, up to 2.5 cm long. Flowers almost sessile. Pods densely ferruginous velvety, 1- (or 2-)seeded |
| 15' | Stipules connate at the base. Inflorescences much longer, 5-55 cm long. Flowers distinctly pedicelled |
| 16 | Inflorescences 5-7 cm long. Pedicels 5-6 mm long. Pods finely rugulose |
| 16' | Inflorescences much longer, 12-55 cm long. Pedicels less than 2.5 mm. Pods (as now known) smooth |
| 17 | Climber. Inflorescences pendulous, up to 55 cm long, rachis glabrous. Ovary 2-ovuled |
| 17' | Tree. Inflorescences erect or pendulous, 12-45 cm long, rachis (densely) puberulous. Ovary 3-5-ovuled |
| 18 | Inflorescences erect, up to 12 cm long. Bracteoles at the apex of pedicel. Filaments of stamens 3-7(-10) mm |
| 18' | Inflorescences pendulous, up to 45 cm long. Bracteoles on the pedicel. Filaments of stamens up to 12 mm |
| 19 | Leaves 9-13-foliolate. Pedicels 6-15 mm, with 2 bracteoles at the middle. Ovary 1- or 2-ovuled; style very short, c. 2 mm |
| 19' | Leaves usually less than 9-foliolate |
| 20 | Inflorescences pendulous, 20-31 cm long |
| 20' | Inflorescences erect, usually 9-17 cm long |
| 21 | Pedicels (1.5-3 mm) articulated at the apex |
| 21' | Pedicels (2-7 mm) articulated at the base |
| 22 | Leaves (2- or) 3- or 4-foliolate. Calyx lobes broadly ovate or suborbiculate, 3-4 by 2.5-3 mm. Style very short, c. 3 mm |
| 22' | Leaves 5- or 6(-8)-foliolate. Calyx lobes elliptic, 5-6 by 3 mm. Style long, up to 12 mm |
| 23 | Pedicels 6-15 mm, articulated at the apex. Ovary 2- (or l-)ovuled. Style c. 2 mm. Leaves 6-9- (or 10-)foliolate |
| 23' | Pedicels usually shorter, 2-5(-6) mm |
| 24 | Pedicels articulated at the apex |
| 24' | Pedicels articulated at the base |
| 25 | Leaves 7- or 8-foliolate. Ovary 2- or 3-ovuled; style very short, 1-2.5 mm. Pods rather small, 2.5-4 by 1.5-2 cm |
| 25' | Leaves 3- or 4-foliolate. Ovary 4(-6)-ovuled; style up to 6 mm. Pods unknown |
| 26 | Filaments of stamens alternately longer and shorter |
| 26' | Filaments of stamens almost equal in length |
| 27 | Leaves 3-7-foliolate. Bracts small, 1-1.5 mm long. Ovary (3- or) 4-ovuled; style 3.5-6 mm |
| 27' | Leaves 3- or 4-foliolate. Bracts larger, up to 4 mm long. Ovary 2(-4)-ovuled; style c. 8 mm |
