290 LEGUMINOSAE (PEA FAMILY) 



unit. H> 1 ") mm. long, pendulous, glabrous, cuspidate. Colorado to Nebraska 

 and far northward. 



54. Astragalus Grayi Parry, Wats. Am. Nat. 8: 212. 1873. Distinguished 

 from the last by the broader leaflets, quite strongly veined, and by the some- 

 what thinner ascending pod: flowers light yellow. Through the western half 

 of Wyoming. 



.">.">. Astragalus flaviflorus (OK.) Sheld. 1. c. 158. Canescent with appressed 

 hairs; diffusely branched and decumbent: leaflets 5-11, oblong or lanceolate- 

 linear, subacute, glabrate above: peduncles longer than the leaves; spikes 

 becoming elongated and loose: the subulate calyx-teeth nearly as long as the 

 campanulate tube: corolla yellow: pod short, mostly included in the calyx, 

 strongly obcompressed and with a broad furrow below. A. flavus. Western 

 Wyoming and Colorado and westward. 



56. Astragalus gracilis Nutt. Gen. 2: 100. 1818. Subcinereous; stems 

 slender, virgate, 2-4 dm. high: leaflets 11-17, linear or filiform: racemes dense, 

 elongated, long-peduncled ; flowers pale purple or whitish: pods spreading, 

 coriaceous, elliptic-ovate, strongly concave dorsally, white-hairy or at length 

 glabrous, transversely rugose-veined, wholly 1-celled, the ventral suture 

 thick and prominent, 4-5 mm. long. Extending from the mountains east to 

 the Missouri. 



57. Astragalus microlobus Gray, Proc. Am. Acad. 6: 203. 1866. Closely 

 allied to the foregoing but the stems diffuse: leaflets shorter, linear or oblong- 

 linear: racemes rather short and usually loosely flowered; flowers deep purple: 

 pods reflexed, thick-cartilaginous, puberulent, finely rugulose, a little flat- 

 tened on the back, the ventral suture very thick. Same range as the pre- 

 ceding. 



58. Astragalus viridis (Nutt.) Sheld. 1. c. 118. Caulescent but depressed- 

 spreading, intricately branched from a long root, hoary with a short silky 

 pubescence: leaflets 5-7, linear-subulate, usually rigid and' divaricate, pungent: 

 flowers 1-3, sessile in the axils of the leaves, ochrcleucous or tinged with 

 violet: pods ovate, sessile, compressed, pubescent, acuminate, somewhat in- 

 curved, usually 1-seeded. A. Kentrophyta. (A. viridis impensa Sheld. 1. c.) 

 New Mexico to Canada and west to Nevada. 



59. Astragalus aculeatus A. Nels. Bull Torr. Bot. Club 26: 10. 1899. 

 Very similar to the foregoing, even more caespitose-depressed, greener with 

 merely a sparse hirsutulous pubescence: leaflets 5-7, plane, involute, or some- 

 what channeled, pungently long-mucronate : flowers purp*le, 6-8 mm. long: 

 calyx-lobes slender, as long as the campanulate tube, hirsute (a few of the 

 hairs black): pod narrowly ovate, acuminate, scarcely exceeding the calyx- 

 lobes. [A. Wolfii Rydb. Bull. Torr. Bot. Club 31 : 562. 1904.] Mostly alpine 

 and subalpine; Colorado to Montana and Idaho. 



60. Astragalus caespitosus (Nutt.) Gray, 1. c. 230. Silvery-canescent and 

 densely depressed-caespitose, forming broad mats: leaves crowded on the 

 crowns, simple, or more rarely 3-5-foliolate, linear-lanceolate to linear-spatu- 

 late, tapering to a slender petiole-like base: peduncles slender, 3-8 cm. long, 

 much surpassing the leaves; the raceme several-flowered; flowers small, pur- 

 ple: pod oblong-lanceolate, acuminate, compressed and thin-edged above, pu- 



it when young. A. spatulatus Sheld. 1. c. 22. Colorado to Montana. 

 (.1. Astragalus simplicifolius (Nutt.) Gray, Proc. Am. Acad. 6: 231. 1866. 

 Appn . <1 silky-pubescent, growing in broad cushioned mats: leaves simple, 

 (i rj nun. long, spa tulate-lanceolate, acute, frequently involute, crowding 

 remit ies of the short branches: scapes 2-3-flowered, scarcely if at all 

 exceeding the leaves; flowers purple: calyx-teeth nearly as long as the tube: 

 pod coriaceous, the ventral suture straight and acute, the dorsal gibbous. 

 (A. ////.V////////.S Sheld. 1. c.; A. fjrilif<>lhis A. Xels. Bull. Torr. Bot. Club 26: 10. 

 is'.Mi.) Drv sterile slopes and plains; Colorado and Wyoming. 



<)'_'. Astragalus tenellus Pursh, Fl. Am. Sept. 2: 473. 1814. Perennial, 



somewhat glahrous: stems several, branched, 2-4 dm. high: stipules dark, at 



'ie lower sheathing; leaflets 11 21, linear or narrowly oblong, acute or 



Obtuse, 7 12 nun. long: peduncles not exceeding the leaves, few-flowered; 



