136 LEGUMINOS^E. (PULSE FAMILY.) 



+- +- Pod not completely 2-celled. 

 M- Pod stipitate, pendent. 



8. A. alpinus, L. Dijj'use (6-12' high), smooth or slightly hairy ; leaf- 

 lets 13 - 25 ; flowers violet-purple, or at least the keel tipped with violet or blue ; 

 calvx campaiiulate ; pod narrowly oblong, short-acuminate, black-pubescent, 

 triangular-turgid, deeply grooved on the back, straight or curved, its stipe usu- 

 allv rather exceeding the calyx. Rocky banks, Lab. to Maine and N. Vt. 



9. A. Robbinsii, Gray. Nearly smooch and erect (1 high), slender; 

 leaflets 7-11; calyx more oblong ; flowers white; pod oblong (6" long), ob- 

 tuse or acutish, minutely darkish-pubescent, somewhat laterally compressed, not 

 dorsaUy sulcate or obsoletely so, straight or somewhat incurved, rather ab- 

 ruptly narrowed at base into the often included stipe. Rocky ledges, Vt. 



10. A. racemosus, 1'ursh. Stout (1-2 high), erect or ascending, ap- 

 pressed-pubescent or glabrate; leaflets 13-25; flowers numerous, white, pen- 

 dent; calyx campanulate, gibbous, white-pubescent; pod straight, narrow, 

 I' long, acute at both ends, triangular-compressed, deeply grooved on the back, 

 the ventral edge acute. Neb. to Mo., and westward. 



** -w- Pod sessile. 



11. A. gracilis, 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. distortus, Torr. & Gray. Low, diffuse, many-stemmed, subgla- 

 brous; leaflets 17-25, oblong, emarginate ; flowers in a short spike, pale-purple; 

 pod ovate- or lance-oblong, curved, 6-9" long, glabrous, thick-coriaceous, some- 

 what grooved on the back, the ventral suture nearly flat. 111. to Iowa, Mo., 

 Ark. and Tex. 



13. A. Iotifl6rus, Honk. Hoary or cinereous with appressed hairs ; stems 

 very short; leaflets 7-13, lance-oblong; (lowers 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, 

 acuti at In ISP, canescent, the back more or less impressed, the acute ventral 

 suture nearly straight. Sask. to Neb. and Tex., west to the mountains. 



14. A. Missouriensis, 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 (!' long), acute, obtuse at base, pubescent, nearly straight, obcom- 

 pressed or obcompressed-triangular, depressed on the back and the ventral su- 

 ture more or less prominent, transversely rugulose. Sask. to Neb. and N. Mex. 



II. Pod l-celled, neither suture being inflexed or the ventral more intruded than 



the dorsal. PHACA. 



15. A. Cooperi, Gray. Nearly smooth, erect (1 - 2 high) ; leaflets 1 1 - 21, 

 elliptical or oblong, somewhat retuse, minutely hoary beneath ; flowers white, 

 rather numerous in a short spike; calyx dark-pubescent; pod coriaceous, in- 

 flated, ovate-globose (6 - 9" long), acute, glabrous, sliahtli/ sulcate on both sides, 

 cavity webby. Ont. and western N. Y. to Minn, and Iowa. 



