24a. Leaflets linear-oblong, 2 cm. long or less; stamens 5 or 10 (3-6 dm. high) (Partridge Pea) --25. 24b. Leaflets lanceolate-oblong, 2-5 cm. long; 7 stamens with normal anthers and 3 with imperfect anthers (8-15 dm. high) =Wild Senna, Cassia marilandica.= 25a. Anthers 10; flowers 2-4 cm. wide =Partridge Pea, Cassia chamaecrista.= 25b. Anthers 5; flowers 5-10 mm. wide =Partridge Pea, Cassia nictitans.= 26a. Silky-hairy with whitish hairs; flowers marked with purple (3-5 dm. high; summer) =Goat's Rue, Tephrosia virginiana.= 26b. Glabrous or nearly so (summer) (Milk Vetch) --27. 27a. Flowers greenish cream-color (4-10 dm. high) =Milk Vetch, Astragalus canadensis.= 27b. Flowers white (3-5 dm. high) =Milk Vetch, Astragalus neglectus.= 28a. Flowers in heads, umbels, or short dense spikes --29. 28b. Flowers in loose racemes or panicles --42. 29a. Flowers bright-yellow; decumbent or ascending plants (spring and summer) --30. 29b. Flowers white, cream, purple, or red; never yellow --34. 30a. Whole flower only about 2 mm. long; pod coiled --31. 30b. Flowers larger, each one 3-6 mm. long; pod straight (1-4 dm. high) (Hop Clover) --32. 31a. Flowers numerous in each head =Black Medick, Medicago lupulina.= 31b. Flowers in clusters of 2 --20 =Bur Clover, Medicago hispida.= 32a. Stipules linear =Hop Clover, Trifolium agrarium.= 32b. Stipules ovate --33. 33a. Heads densely flowered; flowers 20 or more; upper petal striate when dry =Hop Clover, Trifolium procumbens.= 33b. Heads loosely flowered; flowers usually 10 or fewer; upper petal scarcely striate or not at all =Hop Clover, Trifolium dubium.= 34a. Leaves palmately compound, the 3 leaflets all from the same point (late spring and summer) (Clover) --35. 34b. Leaves pinnately compound, the terminal leaflet on a distinct stalk --39. 35a. Individual flowers sessile, or on very short pedicels --36. 35b. Individual flowers distinctly pedicelled --37. 36a. Heads oblong, on distinct peduncles; calyx longer than the corolla (flowers nearly white; 1-4 dm. tall) =Stone Clover, Trifolium arvense.= 36b. Heads nearly globose, almost sessile, closely subtended by the leaves; corolla longer than the calyx (2-8 dm. high; flowers red-purple) =Red Clover, Trifolium pratense.= 37a. Stems prostrate or creeping; heads long-peduncled, arising from the creeping branches (flower-stalks 1-2 dm. high; flowers white) =White Clover, Trifolium repens.=