3. A. Platténsis, Nutt. Loosely villous; stipules conspicuous; leaflets oblong, often glabrous above; flowers crowded in a short spike or oblong head, cream-color often tinged or tipped with purple; _fruit ovate, pointed_, and with the calyx _villous_.--Gravelly or sandy banks, Minn. to Ind. and Ala., west to Col. and Tex.--Var. TENNESSEÉNSIS, Gray, has the pod oblong and slightly curved, and much less fleshy. May. [*][*] _Pod dry, coriaceous, cartilaginous or membranous, dehiscent._ [+] _Pod completely 2-celled, sessile._ 4. A. mollíssimus, Torr. _Stout, decumbent, densely silky-villous throughout and tomentose_; leaflets 19--29, ovate-oblong; peduncles elongated; spikes dense, with rather _large violet flowers_ (6--12´´ long); pod narrow-oblong (5--9´´ long), glabrous, somewhat obcompressed and _sulcate at both sutures_, at length incurved.--Neb. to Kan. and Tex., west to Col. The most common "loco"-plant, and said to be very poisonous to cattle. 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.