1	Anthers dimorphic, alternately dorsifixed or basifixed, either all equal or alternately longer and shorter; perennial herbs or shrubs, usually glandular and villous, sometimes spiny.		158 Ononis
+	Anthers uniform in size and shape, not alternately basifixed and dorsifixed; annual or perennial herbs, not glandular, variably glabrous or hairy, not spiny		(2)
2 (1)	Petals persisting after flowering; legume included in or slightly exserted from persistent corolla, inflorescence generally an umbel or dense raceme, sometimes headlike; filaments dilated upward.		159 Trifolium
+	Petals deciduous after flowering; legume as long as or longer than calyx; inflorescence various; filaments not dilated upward		(3)
3 (2)	Keel petals acute; prostrate herbs rooting at the nodes; leaves palmately 3-foliolate; flowers 1-3 in long-pedunculate axillary umbels.		160 Parochetus
+	Keel petals obtuse; upright or sprawling herbs, not generally rooting at nodes; leaves pinnately trifoliate; flowers in dense to lax terminal or axillary racemes, or in axillary sessile or shortly pedunculate heads, short racemes, umbels, or rarely solitary		(4)
4 (3)	Flowers in slender racemes; ovules few; legumes indehiscent or tardily 2-valved, ovoid, straight, ca. same length as calyx.		161 Melilotus
+	Flowers in heads, short racemes, sessile umbels, rarely solitary; ovules mostly numerous; legumes indehiscent or dehiscent, linear or coiled, flattened or cylindric, longer than calyx		(5)
5 (4)	Keel and wing petals possessing an explosive pollination mechanism, due to interlocking projections on adjoining faces of petals; legumes mostly spirally coiled, some flattened and curved, scarcely dehiscent, mostly prickly.		162 Medicago
+	Keel and wing petals lacking explosive pollination mechanism; legumes straight or curved, mostly linear, dehiscent or indehiscent, not prickly.		163 Trigonella