KEY TO THE SPECIES 43 



glabrous, linear-oblong or oblanceolate ; spikes short-cylindric, dense ; flowers 

 TV-bite. Frequent ; on dry hills. 



2. Petalostemoii purpurens (Vent.) Eydb. (Violet Prairie-clover). Leaf- 

 lets linear, glabrous, 3-5 ; spikes very dense, oblong or oylindrio ; corolla violet or 

 purple. 



7. GLYCYRRHIZA (Liquorice) 



Erect, perennial herbs, from large sweet roots ; the flowers in peduncled, 

 axillary dense spikes, with anthers of two sizes, and ovary sessile with short rigid 

 style. 



1. Glycyrrhiza lepidota Pursh (Wild Liquorice). Glandular-pubescent ; 

 4-8 dm. high ; leaflets 13-17, mostly lanceolate, entire ; spikes dense ; the peduncles 

 shorter than the leaves ; flowers yellowish-white ; pod lS-15 mm. long, few-seeded, 

 closely beset with hooked prickles. On creek banks and in moist draws. 



8. ASTRAGALUS (Milk Vetch) 



Herbs with odd-pinnate or rarely simple stipulate leaves, flowers in racemes 

 or spikes, calyx tubular with equal teeth, clawed petals emd a dehiscent or inde- 

 hiscent pod. 



* Flowers white or yellowish (rarely purple) § 1, 2, 5, and 6. 



* * Flowers blue, violet or purple § 3, 4, 7, 8, and 9. 



§ 1. Stems prostrate ; leaflets 15-25 ; flowers yellowish or purple ; pod thick- 

 walled and fleshy, 2-celled. 



1. Astragalus prunifer Rydb. (Plum-bearing Vetch). The depressed leafy 

 stems 2-3 dm. long, somewhat strigose, as are also the leaves ; leaflets 17-25 ; spike 

 short, peduncled ; flowers yellowish, the keel purple-tipped ; pod plum-shaped, 2 

 cm. long. Saline plains and slopes. Wyoming and northward. 



2. Astragalus crassicarpus Nutt. (Ground Plum). Similar, but with purple 

 flowers and broader leaves. Colorado and eastward. 



§ 2. Tall ; leaflets 15-27 ; flowers yellowish ; pod leathery, 2-celled, oblong, 

 terete. 



3. Astragalus Carolinianus L. (Carolina Milk-vetch). Erect, 4-8 dm. 

 high, glabrous or nearly so ; flowers in dense spikes ; pod sessile, acute, 12-15 mm. 

 long, indehiscent. Common ; on wet banks. 



§ 3. Bushy-branched ; leaflets 19-85 ; flowers violet-purple ; pod glabrous and 

 grooved at both sutures, 2-celled. 



4. Astragalus molllssimus Torr. (Woolly Loco-weed). Densely pubescent, 

 with long soft hairs, 3-4 dm. high ; the stem proper short ; the peduncles long and 

 scape-like ; flowers in dense spikes. The commonest of the Colorado " Loco- 

 weeds." 



§ 4. Low, spreading or assurgent ; leaflets 15-25 ; flowers purplish or violet ; 

 pod pubescent, 2-celled. 



5. Astragalus adsurgens Pall. (Ascending Mjlk-vetch). Tufted, the 

 numerous stems decumbent at base with ascending tips ; leaflets oblong, cin- 

 erous ; spikes dense, capitate or cylindric ; pod leathery, grooved dorsally, 10-12 

 mm. long. 



