66 LEGUMINOS^E. (PULSE FAMILY.) 



*-* -M. Caulescent, rather tall, leafy: lea/lets 7 to ^-paired: racemes or spikes mostly 

 many-flowered: pod with a stipe equalling or exceeding the calyx. 



38. A. frigidus, Gray, var. Americanus, Watson. Subglabrous : 

 leaflets ovate- or elliptic-oblong : peduncles equalling the leaves : flowers 

 white: pod oblong, acute at each end, black-hairy or glabrous. Bibl. Index, 

 i. 193. A. frigidus of Bot. King's Exp., Hayd. Rep. 1871, and Fl. Colorado. 

 In the mountains from Colorado to the Arctic regions. 



15. Pod membranous, lanceolate-cylindric, straight, exsertly-stipitate, glabrous: 

 flowers rather large: leaflets few or almost none, 



39. A. lonchocarpus, Torr. Ashy-puberulent, glabrate : stem fistulous, 

 branched : leaflets filiform-linear, remote, the leaf sometimes reduced to the 

 flattened-filiform rachis : racemes loosely many-flowered : flowers white, pen- 

 dent : pod very sharply acuminate at each end. Pac. R. Rep. iv. 80. S. Colo- 

 rado to New Mexico and Utah. 



16. Pod membranous or chartaceous, small, globose or ovate, inflated, sessile. 

 Diffuse or procumbent, mostly small and slender: flowers small and usually few. 



40. A. microcystis, Gray. Ashy-pubescent, from a woody root : leaflets 

 4 to 6 pairs, oblong or oblong-lanceolate, obtuse : racemes 5 to 1 2-flowered : corolla 

 violet or whitish : pod globose-ovate, 3 lines long, thin membranous, gray-pubes- 

 cent. Proc. Am. Acad. vi. 220. W. Wyoming (Parry) and Washington 

 Territory. 



41. A. leptaleUS, Gray. Nearly glabrous: leaflets 7 to 11 pairs, lance- 

 linear or oblong, often acute : peduncles 2 to 4-flowered : corolla white : pod ovate 

 or oval, 4 lines long, chartaceous, puberulent. Loc. cit. Colorado. 



42. A. jejunus, Watson. Dwarf, minutely hoary-pubescent: stems 1 to 2 

 inches long, crowded, from a many-branching caudex, covered with numerous 

 imbricated stipules, which are membranous, sheathing, truncate and ciliate: 

 leaflets 4 to 7 pairs, linear: peduncles 2 to 3-flowered : corolla ochroleucous or 

 tinged with violet: pod gibbous dorsally, obtuse, 4 lines long, membranous, gla- 

 brous. Bot. King's Exp. 173, t. 13. Bear River Valley, near Evauston 

 ( Watson). 



43. A. humillinitlS, Gray. Habit of the last, but much more dwarf and 

 condensed : stems scarcely an inch long, with the 'scarious coalescent stipules imbri- 

 cate and petioles persistent and spinescent : leaflets 3 to 5 pairs, oblong, canescent, 

 with revolute margins: peduncles 1 to 3-flowered: corolla pale: pod ovate, 2 

 lines long, coriaceous, with a white pubescence. Proc. Am. Acad. xii. 57. Often 

 choked in drifting sand. Mesa Verde, S. W. Colorado (Brandegee). 



1 7. Pod coriaceous, shortly exsert-stipitate, straight, narrowly oblong, semi-cylin- 

 dric, the deeply concave ventral surface divided by the salient obtuse suture. 



44. A. bisulcatUS, Gray. Strigulose-puberulent : stem over a foot high, stout: 

 leaflets oblong, often narrower : flowers violet, in dense spike-like racemes, middle- 

 sized : calyx-teeth scarcely shorter than the tube. Pac. R. Rep. xii. 42, t. 1 . 

 From Colorado to Nebraska and the Saskatchewan. 



45. A. HaydGnianilS, Gray. Smaller, pubescence more cinereous : spike 

 elongated, virgote : flowers much smaller : calyx-teeth much shorter than the tube : 

 corolla white, keel tinged with purple at the end: pod rugulose with transverse 

 veins; stipe not exceeding the calyx. Proc. Am. Acad. xii. 56. Colorado. 



