Herbs, erect or diffuse. Leaves uni, very rarely trifoliolate, leaflets 2-stipellate; stipules scarious, acuminate, free or connate. Inflorescence terminal and axillary a raceme or panicle, flowers often in pairs, bracts scarious and deciduous. Calyx deeply divided, 2 upper lobes often connate to the apex. Corolla generally not exserted; vexillum obovate or orbicular, narrowed into a claw, wings obliquely oblong, adhering to the keel. Keel slightly incurved, often appendaged. Stamens diadelphous, 9+1, anthers uniform. Ovary sessile or stipitate, ovules many, style filiform, curved at the apex. Stigma terminal capitate. Fruit constricted between seeds.