| 1 | Plant viscid; leaflets 2 (or 1) pairs; stamens 5; staminodes absent. |
| 1' | Plant not viscid; leaflets 6-many pairs; stamens usually 10, rarely fewer |
| 2 | Petiolar gland distinctly stipitate |
| 2' | Petiolar gland sessile |
| 3 | Tree; leaflets 10-14 pairs, 4-5 mm broad; pods 3- or 4-seeded |
| 3' | Herb; leaflets usually more than 15 pairs, 1-2.5 mm broad; pods 8-15-seeded. |
| 4 | Leaf rachis not canaliculate. Ovary with short, stiff appressed hairs; pods with scattered appressed hairs |
| 4' | Leaf rachis canaliculate. Ovary woolly, with longer, thinner hairs. Pods with long and short, not appressed hairs |
