PAPILIONACEAE. 



[VOL. II. 



16. Astragalus gracilis Nutt. Slen- 

 der Milk Vetch. (Fig. 2140.) 



Dalea parviflora Pursh, Fl. Am. Sept. 474. 

 Not A. pannftorus Lam. 1783. 



1814. 



' 



Astragalus gracilis Nutt. Gen. 2: 100. 1818. 



Slender, erect, finely pubescent, i-2 high, 

 simple or nearly so. Stipules ovate, acute or 

 acuminate, 2 // -3 // long; leaflets 11-21, narrowly 

 linear, distant, obtuse at the apex, 9 // -i2 // long, 

 scarcely i" wide; flowers purple, $"-4" long, 

 in narrow elongated spike-like racemes; pedi- 

 cels i" long or less; pods i -celled, sessile in the 

 calyx, pendent, straight, coriaceous, ellipsoid, 

 finely appressed-pubescent with white hairs, 

 especially on the ventral side, transversely 

 .veined, a // -3 // long. 



Prairies, Minnesota to Missouri, Colorado and 

 Wyoming. May-June. 



.17. Astragalus microlobus A. Gray. 

 Notched-leaved Milk Vetch. ( Fig. 2141.) 



Astragalus microlobus A. Gray, Proc. Am. Acad. 6: 203. 

 1864. 



Diffuse or ascending, finely canescent, about i 

 high. Stipules ovate-lanceolate, acute, i%"-i" 

 long; leaflets 7-17, linear or linear-oblong, truncate 

 or emarginate at the apex, narrowed at the base, 4"- 

 7" long; flowers purple, J/'-Q," long, in loose spikes; 

 peduncles often longer than the leaves; pod sessile, i- 

 celled, coriaceous, ovoid or ellipsoid, reflexed, finely 

 pubescent, transversely veined, flattened on the 

 back, keeled along the ventral suture, a"-3" long. 



Prairies, Nebraska to Missouri and Colorado. Similar 

 to A. gracilis. Summer. 



18. Astragalus flexuosus (Hook.) Dougl. 

 Milk Vetch. (Fig. 2142.) 



Flexile 



Phaca elongata Hook. Fl. Bor. Am. i: 140. 1830. Not Astraga- 

 lus elongatus Willd. 1803. 



Phaca flexuosa Hook. Fl. Bor. Am. i: 141. 1830. 

 Astragalus flexuosus Dougl.; Hook. Fl. Bor. Am. i: 140. 1830. 



Erect or ascending, finely pubescent, branching from the 

 base, i-i}4 high. Stipules ovate or ovate-lanceolate, 2 // ~3 // 

 long; leaflets 9-21, linear, oblong or oblanceolate, obtuse 

 or emarginate at the apex, narrowed or cuneate at the base, 

 3 // -6 // long; peduncles exceeding the leaves; flowers purple 

 or purplish, 4 // -5 // long; pod i-celled, sessile, cylindric, linear 

 or linear-oblong, puberulent, dehiscent, pointed, 8 // -i2 // long. 



Prairies, Nebraska to Colorado, north to the Northwest Terri- 

 tory. June-Aug. 



