302 PAPILIONACEAE. [Vor. II. 
16. Astragalus gracilis Nutt. Slen- 
der Milk Vetch. (Fig. 2140.) 
Dalea parviflora Pursh, Fl. Am. Sept. 474. 1814. 
Not A. parviflorus Lam. 1783. 
Astragalus gracilis Nutt. Gen. 2: 100, 1818. 
Slender, erect, finely pubescent, 1°-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’’—12’’ long, 
scarcely 1// wide; flowers purple, 3-4” long, 
in narrow elongated spike-like racemes; pedi- 
cels 1/’ long or less; pods 1-celled, sessile in the 
: calyx, pendent, straight, coriaceous, ellipsoid, 
SS a finely appressed-pubescent with white hairs, 
4 especially on the ventral side, transversely 
veined, 2’’-3/’ long. 
Prairies, Minnesota to Missouri, Colorado and 
Wyoming. May-June. 
17. Astragalus microlobus A. Gray. 
Notched-leaved Milk Vetch. (Fig. 2141.) 
ees microlobus A, Gray, Proc. Am. Acad. 6: 203. 
1864. 
Diffuse or ascending, finely canescent, about 1° 
high. Stipules ovate-lanceolate, acute, 134//-2/’ 
long; leaflets 7-17, linear or linear-oblong, truncate 
or emarginate at the apex, narrowed at the base, 4’/— 
7// long; flowers purple, 3’’-4’’ 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, 2/’-3/’ long. 
Prairies, Nebraskato Missouri and Colorado. Similar 
to A. gracilis. Summer. 
18. Astragalus flexudsus (Hook.) Dougl. Flexile 
Milk Vetch. (Fig. 2142.) 
Phaca elongata Hook. Fl. Bor. Am. 1: 140. 1830. Not Astraga- 
lus elongatus Willd. 1803. 
Phaca flexuosa Hook, Fl. Bor. Am, 1; 141. 1830. 
Astragalus flexuosus Dougl.; Hook. Fl. Bor. Am. 1: 140. 1830. 
Erect or ascending, finely pubescent, branching from the 
base, 1°-1%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 1-celled, sessile, cylindric, linear 
or linear-oblong, puberulent, dehiscent, pointed, 8’’-12// long. 
Prairies, Nebraska to Colorado, north to the Northwest Terri- 
tory. June-Aug. 
