5. A. Canadénsis, L. Tall and erect (1–4° high), somewhat pubescent or glabrate; leaflets 21–27, oblong; flowers greenish cream-color, very numerous, in long dense spikes, pods crowded, oblong (6´´ long), glabrous, terete, scarcely sulcate and only on the back, nearly straight.—River-banks, western N. Y. to N. Ga., and far westward.
6. A. adsúrgens, Pall. Ascending or decumbent (4–18´ high), cinereous with minute appressed pubescence or glabrate; leaflets about 21, narrowly or linear-oblong; spike dense, with medium-sized pale or purplish flowers; pubescence of calyx appressed; pod oblong (4–5´´ long), finely pubescent, triangular-compressed, with a deep dorsal furrow, straight.—Red River valley, Minn., to W. Kan., and westward. (Asia.)
7. A. hypoglóttis, L. Slender (6´–2° long), diffusely procumbent or ascending, with a rather loose pubescence or nearly glabrous; leaflets 15–21, oblong, obtuse or retuse; flowers violet, capitate; calyx loosely pubescent; pod as in the last, but ovate and silky-villous.—Red River valley, Minn., to central Kan. and westward.
[+][+] Pod not completely 2-celled.
[++] Pod stipitate, pendent.
8. A. alpìnus, L. Diffuse (6–12´ high), smooth or slightly hairy; leaflets 13–25; flowers violet-purple, or at least the keel tipped with violet or blue; calyx campanulate; pod narrowly oblong, short-acuminate, black-pubescent, triangular-turgid, deeply grooved on the back, straight or curved, its stipe usually rather exceeding the calyx.—Rocky banks, Lab. to Maine and N. Vt.
9. A. Robbínsii, Gray. Nearly smooth and erect (1° high), slender; leaflets 7–11; calyx more oblong; flowers white; pod oblong (6´´ long), obtuse or acutish, minutely darkish-pubescent, somewhat laterally compressed, not dorsally sulcate or obsoletely so, straight or somewhat incurved, rather abruptly narrowed at base into the often included stipe.—Rocky ledges, Vt.
10. A. racemòsus, Pursh. Stout (1–2° high), erect or ascending, appressed-pubescent or glabrate; leaflets 13–25; flowers numerous, white, pendent; calyx campanulate, gibbous, white-pubescent; pod straight, narrow, 1´ long, acute at both ends, triangular-compressed, deeply grooved on the back, the ventral edge acute.—Neb. to Mo., and westward.
[++][++] Pod sessile.
11. A. grácilis, Nutt. Subcinereous, slender (1° high or more); leaflets 11–17, linear, obtuse or retuse; racemes loose; flowers small (3´´ long); pods pendent, 2–3´´ long, coriaceous, elliptic-ovate, concave on the back, the ventral suture prominent, white-hairy, at length glabrous, transversely veined.—Minn. to Neb. and Mo., and westward.