1	Inflorescence axis ending in spine, hairs biramous, anthers apiculate		Indigofera
+	Inflorescence, hairs and anthers not as above		(2)
2 (1)	Branches ending in spines		(3)
+	Branches not ending in spines		(5)
3 (2)	Fruit 1-9-seeded, slightly constricted between seeds		Alhagi
+	Fruit 1-2-seeded, not constricted between seeds		(4)
4 (3)	Fruit suborbicular, compressed, crested or prickly (not glandular pubescent)		Onobrychis
+	Fruit ovate, glandular pubescent		Ononis
5 (2)	Leaf rachis spiny		(6)
+	Leaf rachis not spiny		(8)
6 (5)	Fruit 1-seeded, compressed, enclosed in the calyx		Ebenus
+	Fruit not as above		(7)
7 (6)	Calyx very oblique		Caragana
+	Calyx not oblique		Astragalus
8 (5)	Stipules spiny		(9)
+	Stipules not spiny		(12)
9 (8)	Leaflets serrate		Cicer
+	Leaflets entire		(10)
10 (9)	Deciduous tree, stamens 10, monadelphous		Robinia
+	Shrubs or undershrubs, stamens diadelphous		(11)
11 (10)	Calyx very oblique		Caragana
+	Calyx not oblique		Astragalus
12 (8)	Tree, vexillum much longer than keel		Erythrina
+	Shrubs or small trees, vexillum not much longer than the keel		(13)
13 (12)	Fruit jointed		Aeschynomene
+	Fruit not jointed		Sesbania