Medicago

Herbs, rarely shrubs. Leaves pinnately 3-foliolate, veins of leaflets usually extended into teeth on margin; stipules entire, dentate, incised or laciniate. Flowers yellow, purple, mauve or pale lilac, in axillary racemes or heads, or sometimes subsolitary; bracts small or 0. Calyx with campanulate tube; lobes longer than tube. Petals: vexillum sessile; wings oblong, eared, clawed; keel shorter than wings, obtuse, with a linear claw. Stamens diadelphous, with vexillary stamen free; filaments with uniform anthers. Ovary sessile or subsessile, sometimes twisted, sometimes papillose, (1)- several- to many-ovuled; style variable, with oblique, subcapitate stigma. Pod spirally falcate, often spiny, often hooked, or somewhat curved and unarmed. Seeds ovoid, slightly reniform, partitioned or nonpartitioned, pale yellow to yellow-brown. x= 7, 8, 9 (high polyploidy).