193 



Stems sparingly branched and strangling upward, 1-2 ft, high. 



155 gracilentus. 

 2A23. Pods cylindrical, acute, about 2 cm. long, little 



oblique or much inflated, arcuate, sessile. 156 coriaceus. 



2A3B Pods not cylindrical. 



Pods straight, ovate, stipitate. 157 Antoninus. 



Pods oblanceolate. 158 pinonis. 



Pods immature and very hairy. 159 Neomexicanus. 



3A. Slender and prostrate plants with nearly simple stems 2-3 ft. 



long. Leaves distant, nearly sessile, divaricate. Peduncles long 



and divaricate. Flowers capitate. Pods rigid, 1-2.5 cm. long. 



160 Sileranus. 



152 Astragalus parviflorus (Pursh Fl. 474 as Dalea) MacAIillan 

 ^letasperm. 325 (1892). A. microlobus Gray. Pods about oval, trian- 

 gular-apiculate, about straight, 5 mm. long, by 3 mm. wide, barely 1 

 mm. high, in long racemes, refle.xed, on pedicels about 1 mm. long. 

 Flowers pale barely 4 mm. long, many. Banner oval, abruptly bent at 

 end of tube to erect, 3-4 mm. long, with sides reflexed most above. 

 Wing? oblanceolate, rounded, flaring, concave to keel and arched to 

 45 degrees, longer than keel, but much shorter than banner. Keel 

 a ched from base to a half circle and obtuse, barely 2 mm. long. All 

 petals with exserted claws. Calyx hemispherical, about 1 mm. long, 

 with deltoid teeth less than a third as long as tube. Peduncles 1 ft. or 

 so long, narrower than the stems, rather appressed as well as the 

 leaves, with flowers racemosely spicate on the upper half and ap- 

 iires^ed till nearly mature then flowers spreading to reflexed. Leaves 

 rarely 7 cm. long, with 2-4 pairs of narrowly linear leaflets nearly 2.5 

 cm. long. Stems weakly erect, almost filiform, 1-2 ft. long, with ra- 

 ther long internodes. Park Co. Montana to Kansas, Minnesota and 

 Missouri on prairies and plains, in May and June. 



Astragalus parviflorus var. microlobus (Gray Proc. Am. Acad. 6 

 203 1864 as species). This is a more robust and more branched form 

 with pods often 8 mm. long, 3-5 mm. wide and 2 mm. high, and a little 

 longer and narrower and somewhat arched and less obcompressed, 

 the calyx tube is about 2 mm. long, the flowers 7-8 mm. long and the 

 l)anner purple-striped. Leaflets 4-8 pairs, oblong to broadly linear or 

 oblanceolate, rarely over 1 cm. long, mostly notched. .Stems rather 

 spreading or subdecumbent and widely branched. This is the com- 

 mon form central Montana to southwestern Kansas and Colorado, in 

 the foothills on the Atlantic slope in Colorado. 



253 Astragalus flexuoius Douglas in Hook. Fl. Bor. Am. 1 141 

 (1830). Pods 1-2.5 cm. long, short-stiiptate, rather rugulose, about 

 smooth, in the type nearly round in cross-section or a little higher 

 than wide, rather wider above, the ventral suture straight and not 

 sulcata, the dorsal suture little or not at all sulcate, the triangular tip 

 rarely 1 mm. long and is also straight and in line with the ventral su- 

 ture. Flowers often purplish, in loose and rather short racemes. 

 Hanncr oblong, abruptly arched beyond calyx teeth to 45-90 degrees, 

 rot over 7 mm. long. Wings nearly as long as banner, arched, nar- 

 rowly oblong, obtuse. Keel about 2 mm. shorter than wings, 3 mm. 

 long, 1 mm. wide, with straight base and then abruptly arched to erect 

 .•'.t the obtuse tip which is purple and 2 mm. high. Calyx tube about 3 

 1 im. long, triangular-campanulate, very oblique at tip, equally inserted, 

 ;-hy or nigrescent, teeth deltoid or triangular, rarely one fourth as 

 ' mg as tube. Pedicels 1-2 mm. long, rather longer than the ovate 

 I'facts. Peduncles 1-3 dm. long, (the rachis often as much more in 

 fruit), longer than the leaves, slender, somewhat spreading, in all but 



