518 FABACEAE 



Stipules adnate to the petioles only slightly at the base; pods pendent, 1-celled, many 



times exceeding the calyx; plant often caulescent. I. DEFLEXI. 



Stipules decidedly adnate to the petioles; pods not pendent; plant acaulescent. 

 Leaves strictly pinnate; leaflets opposite. 



Fruiting calyx inflated, enclosing the fruit; plants densely cespitose, less than 



1.5 dm. high. II. NANI. 



Fruiting calyx not inflated, much exceeded by the pod. 

 Inflorescence 1-3-flowered; plants dwarf, pulvinate. 



Pods inflated, 1-celled, ovoid. III. INFLATI. 



Pods not inflated, oblong, almost 2-celled. IV. PARRYANI. 



Inflorescence many-flowered; plants mostly over 1.5 dm. high, not pulvinate; 



pod oblong, not inflated. V. CAMPESTRES. 



Leaflets verticiUate. VI. VERTICILLARES. 



I. DEFLEXI. 

 Plant more or less caulescent; racemes at least in fruit elongate; pods 1.5-1.8 cm. long. 



1. A. deflexus. 

 Plant subacaulescent; racemes short and head-like; pods about 1 cm. long. 



2. A. foliolosus. 

 II. NANI. 



Peduncles scarcely exceeding the leaves, 1 3-flowered; bracts broadly ovate. 



Leaflets 5-10 mm. long; corolla 20-25 mm. long. 3. A. multiceps. 



Leaflets 36 mm. long; corolla about 15 mm. long. 4. A. minor. 



Peduncles decidedly exceeding the leaves, many-flowered; bracts lanceolate or ovate- 

 lanceolate. 

 Pubescence of the peduncles appressed or merely ascending; pods included in the 



calyx. 

 Peduncles erect, strict; spike oblong, over 2 cm. long. 



Corolla yellow or whitish, more than 2 cm. long. 5. A. collinus. 



Corolla purple, less than 2 cm. long. 6. A. Blankinshipii. 



Peduncles ascending, curved; spike subcapitate. 7. A. nanus. 



Pubescence of the peduncles loosely spreading; pods usually somewhat exserted. 



8. A. Lagopus. 

 III. INFLATI. 

 Leaflets 11-23. 



Leaflets sparingly appressed-hirsute. 9. A. podocarpus. 



Leaflets densely canescent. 10. A. Hallii. 



Leaflets 511, densely canescent. 11. A. oreophilus. 



IV. PARRYANI. 

 One species. 12. A. Parryi. 



V. CAMPESTRES. 

 Plant not viscid. 



Corolla purple, rarely white. 

 Calyx with spreading hairs. 



Calyx white-hairy ; corolla usually light purple. 



Plant loosely pubescent; peduncles with long spreading hairs. 



8. A. Lagopus. 

 Plant silky-canescent ; peduncles with appressed hairs. 



Plant low, densely cespitose; peduncles ascending, curved, less than 



5 cm. high; spike capitate. 13. A. argophyllus. 



Plant taller, over 1 dm. high; spike elongate. 



Calyx long-hairy; wings broad. 14. A. Besseyi. 



Calyx short-hairy ; wings narrow. 21. A. albertinus. 



Calyx black-hairy; corolla dark, bluish purple. 



Plant white or grayish villous. 15. A. atropurpureus. 



Plant silky, with appressed hairs, green. 16. A. melanodontus. 



Calyx with appressed hairs. 



Legumes about 3 cm. long, short-stipitate and long-acuminate; corolla over 2 



cm. long. 17. A. Bigelovii. 



Legume 2 cm. long or less, sessile. 



Legumes villous, almost 2-celled; caudices densely white-hairy; corolla 12 



mm. long. 18. A. plattensis. 



Legumes appressed-silky or short-hairy ; caudices not conspicuously white- 

 hairy. 

 Legume nearly 2-celled; leaves white-silky. 



Corolla 12-15 mm. long; wings slightly emarginate. 



19. A. monticola. 

 Corolla about 2 cm. long; wings broadly and deeply emarginate. 



20. A. sericeus. 

 Legumes only half 2-celled. 



Leaves white-silky beneath; corolla 15 mm. long; pod ascending. 



21. A. albertinus. 

 Leaves green or only slightly silky. 



Legumes spreading; leaves elliptic or oblong; corolla 15 mm. 



long. 22. A. dispar. 



Legumes erect or strongly ascending ; leaflets lanceolate or linear- 

 lanceolate, very acute. 



Leaves spreading; pod 15 mm. long, abruptly contracted 

 into a short spreading beak; corolla 15 mm. long. 



23. A. angustatus. 



Leaves erect; pod 20 mm. long, long-acuminate, nearly 

 straight; corolla 18-20 mm. long. 24. A. Lambertii. 



