| 1 | Perennials; leaflets broad, 3-20 mm wide, with conspicuous bronze or purple veins; inflorescences many-flowered, rather congested; petals pale creamy yellow pencilled purple or red; pods unarmed or feebly spinulose, papery |
| 1' | Annuals; leaflets narrow, 1-4 mm wide, without colored veins; inflorescences few-flowered; petals pink, magenta or purple; pods rigidly spinose |
| 2 | Peduncles generally much longer than subtending leaves; pod with a crest of regular deltoid lobes |
| 2' | Peduncles generally shorter than subtending leaves |
| 3 | Pods with a crest of slender spines; calyx-tube glabrous |
| 3' | Pods with a crest of flattened, deltoid or truncate, denticulate lobes; calyx-tube +/- pilose |
