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. 12. A. distórtus, Torr. & Gray. Low, diffuse, many-stemmed, subglabrous; leaflets 17--25, oblong, emarginate; flowers in a short spike, pale-purple; pod ovate- or lance-oblong, curved, 6--9´´ long, glabrous, thick-coriaceous, somewhat grooved on the back, the ventral suture nearly flat.--Ill. to Iowa, Mo., Ark. and Tex. 13. A. lotiflòrus, Hook. Hoary or cinereous with appressed hairs; stems very short; leaflets 7--13, lance-oblong; flowers yellowish, in few-flowered heads, with peduncles exceeding the leaves or very short; _calyx campanulate, the subulate teeth exceeding the tube_; pod oblong-ovate, 9--12´´ long, acuminate, _acute at base_, canescent, the back more or less impressed, the acute ventral suture nearly straight.--Sask. to Neb. and Tex., west to the mountains. 14. A. Missouriénsis, Nutt. Short-caulescent, hoary with a closely appressed silky pubescence; leaflets 5--15, oblong, elliptic or obovate; flowers few, capitate or spicate, 5--8´´ long, violet; _calyx oblong, the teeth very slender_; pod oblong (1´ long), acute, _obtuse at base_, pubescent, nearly straight, obcompressed or obcompressed-triangular, depressed on the back and the ventral suture more or less prominent, transversely rugulose.--Sask. to Neb. and N. Mex. II. _Pod 1-celled, neither suture being inflexed or the ventral more intruded than the dorsal._--PHACA. 15. A. Coòperi, Gray. Nearly smooth, erect (1--2° high); leaflets 11--21, elliptical or oblong, somewhat retuse, minutely hoary beneath; flowers white, rather numerous in a short spike; calyx dark-pubescent; pod coriaceous, _inflated, ovate-globose_ (6--9´´ long), _acute, glabrous, slightly sulcate on both sides_, cavity webby.--Ont. and western N. Y. to Minn. and Iowa. 16. A. flexuòsus, Dougl. Ashy-puberulent, ascending (1--2° high); leaflets 11--21, mostly narrow; flowers small, in loose racemes; pod thin-coriaceous, _cylindric_ (8--11´´ long, 2´´ broad), pointed, straight or curved, puberulent, very shortly stipitate.--Red River Valley, Minn., to Col. 22. OXÝTROPIS, DC.