| 1 | Inflorescence distinctly pedunculate, flowers in a short, often globose, raceme |
| 1' | Inflorescence sessile or subsessile, not pedunculate, or flowers axillary, solitary or in pairs |
| 2 | Pods laterally flattened or strongly compressed |
| 2' | Pods terete or subterete, not strongly compressed or flattened |
| 3 | Pods 1.3-2.3 cm long, falcately upcurved, glabrous, obtuse or subacute |
| 3' | Pods 3-4 mm long, deflexed, thinly pilose, with a slender, upcurved beak |
| 4 | Pods not constricted between the seeds, more or less densely pubescent; leaflets pubescent |
| 4' | Pods constricted between the seeds, papery, thinly pubescent; leaflets glabrous above, thinly pubescent below |
| 5 | Flowers in axillary clusters, minute, standard less than 5 mm long |
| 5' | Flowers solitary or sometimes in pairs, axillary, not minute, standard generally exceeding 1 cm in length |
| 6 | Pod pubescent, 3-7 cm long, narrowing abruptly to a long rigid beak |
| 6' | Pod glabrous (or microscopically glandular) 7-12 cm long, tapering gradually to an apical beak |
| 7 | Valves or pod openly veined; plant 15-40(-50) cm high; petals yellowish-white |
| 7' | Valves of pod closely veined; plant usually much less than 15 cm high; petals blue |
