1Plant viscid; leaflets 2 (or 1) pairs; stamens 5; staminodes absent.
1'Plant not viscid; leaflets 6-many pairs; stamens usually 10, rarely fewer
2Petiolar gland distinctly stipitate
2'Petiolar gland sessile
3Tree; 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.
4Leaf 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