64 LEGUMINOEUB. (PULSE FAMILY.) 



* Annual or biennial, many-stemmed : flowers rather small: pod inflated, mem- 



branous, incurved. 

 27. A. pubentissimus, Torr. & Gray. Dwarf, hirsute-caneseent : leaf- 

 lets oblong or obovate: flowers few: pod villous, ovate-lunate, stronglv in- 

 curved. — Colorado and W. Wyoming. 



* * Perennial, short-stemmed or scarcely caulescent, usually prostrate or matted: 

 flowers rather large : pod thick-coriaceous, obcompressed-triangular, trans- 

 versely rugulose. 



2S. A. Missouriensis, Nutt. Subeaulescent, hoary-silky ivith a short 

 very closely oppressed pubescence : peduncles seape-like, eapitately or spicatelv 

 few-flowered: pod nearly straight, blackish, elliptic. — From New Mexico to 

 Nebraska and the Saskatchewan. 



29. A. Shortianus, Xutt. Usually subacaulescent, silky-cane scent ivith 

 a very closely oppressed pubescence : leaflets obovate or ovate : pod strongly 

 arcuate, thick, puberulent, ovate-lanceolate to lanceolate-linear. — Includes A. 

 cyaneus of most of the western reports. From Colorado to Nebraska and 

 westward ; also southward into New Mexico. 



30. A. Parryi, Gray. Stems short, villous, ivith loose spreading hairs: 

 flowers loosely subcapitate, whitish or yellowish, the keel tinged with purple : 

 l>od arched or at length circinate, pubescent, oblong-lanceolate, strongly obcompressed 

 and rugulose, both sidures sulcately impressed, contiguous. — Am. Jour. Sci. u. 

 xxxiii. 410. From Colorado to N. W. Texas. 



31. A. iodanttuis, Watson. Canescent with an appressed hairy pubes- 

 cence, or usually nearly glabrous with scattered hairs upon the petioles and 

 margins of the leaves: stems decumbent: leaflets obovate or orbicular: spikes 

 short, dense: pod strongly arcuate or hamate, nearly glabrous, mottled, linear-oblong, 

 irregidarly folded. — Bot. King's Exp. 70. Colorado (Coulter) and Nevada. 



32. A. glareosilS, Dougl. Depressed, villous-silky ivith white incumbent 

 hairs: flowers 3 to 6 : pod incun-ed, silky-pubescent becoming subglabrous, oblong- 

 ovate, attenuate above. — Wyoming and S. Idaho. 



Series II. Pod one<elled, neither suture being inflexed or the ventral more 



intruded than the dorsal. — Phaca, L. 

 A. Leaves pinnate with many or rarely ivith few or abortive leaflets, or simple. 



Artificial Key. 



Leaflets prickly pointed and rigid, persistent No. 61 



Leaflets not prickly pointed. 

 Pod inflated, 

 Stipitate, 



Mottled c 36 



Not mottled. 



Stipe very short 37 



Stipe equalling or exceeding the calyx 3S, 39 



Sessile. 



Annual; pod 7 to 12 lines long 34.35 



Perennial ; pod 2 to 4 lines long 40, 41, 42, 43 



Pod coriaceous or cartilaginous, not bladdery inflated, 

 Ex-ert-stipitate, 



Deeply sulcate 44, 45 



Not deeply sulcate 53 



