LEGUMINOSAE (PEA FAMILY) 



281 



SERIES I 



Pods fleshy, somewhat plum-shaped, indehiscent (GEOPRUMNON). 



Flowers ochroleucous, the keel purple-tipped . . . . 1. A. succulentus. 



Flowers purple, often pale . . . . . . . 2. A. crassicarpus. 



Pods not fleshy, dehiscent. 



Pod_ not inflated, membranous or leathery. 



Pods ovate or oblong, leathery (ASTRAGALUS). 

 Plants densely villous-canescent throughout. 



Pods glabrous 3. A. mollissimus. 



Pods woolly 4. A. Bigelovii. 



Plants glabrate or appressed strigose-pubescent. 



Stems erect, 3-10 dm. high; flowers ochroleucous, spreading 



or reflexed in the dense spike . . . . . 5. A. carolinianus. 



Stems ascending, 1-3 dm. high; flowers ascending, in a 



short spike. 

 Stems stoutish; spike oblong; pod sessile. 



Flowers purplish . . . . . . 6. A. nitidus. 



Flowers ochroleucous . . . . . . 7. A. sulphurescens. 



Stems weak, spikes capitate; pod stipitate . . . 8. A. hypoglottis. 

 Pods ascending, broadly linear, flattened, membranous 



(HAMOSA). 

 Caulescent; greenish, sparsely hirsute ..... 9. A. Nuttallianus. 



Acaulescent; silvery-silky ....... 10. A. calycosus. 



Pods conspicuously inflated, papery (CYSTIUM). 



Nearly glabrous throughout 11. A. diphysus. 



Subcinereous or strigillose ....... 12. A. ineptus. 



SERIES H 



Pods deeply sulcate dorsally, this suture being thus deeply intruded 



and the pod obcordate in cross section (TIUM). 

 Stems rather stout, suberect; flowers yellowish; pods 3 cm. or 



more long, exsert-stipitate, spreading or pendent. 

 Plant woolly-pubescent ........ 13. A. Drummondii. 



Plant appressed-pubescent or glabrate. 



Leaflets obovate-oblong, glabrous above .... 14. A. scopulorum. 



Leaflets linear-oblong, glabrate on both faces . . . 15. A. racemosus. 

 Stems slender, flexuous or spreading: flowers not yellow; pods 



less than 2 cm. long, short-stipitate or subsessile. 

 Pods black-hairy; stipe as long as the calyx . . . . 16. A. alpinus. 



Pods pale-pubescent; stipe short or wanting. 



Pods coriaceous, mottled, incurved 17. A. sparsiflorus. 



Pods chartaceous, deflexed ....... 18. A. desperatus. 



Pods slightly if at all sulcate dorsally, one or both of the sutures in- 

 truded but rarely deeply so (the sections Xylophacos and 

 Phaca quite variable). 



Pods membranous, coriaceous or woody, not conspicuously in- 

 flated. 



Pods membranous (ATELOPHRAGMA). 

 Pods exsert stipitate. 



Leaves cinereous-pubescent on both faces . . .19. A. aboriginorum. 



Leaves glabrous or minutely appressed-pubescent beneath. 

 : Pods glabrous ........ 20. A. glabriusculus. 



Pods black-hairy . ' . 21 . A. Macounii. 



Pods sessile or nearly so. 



PoJs reflexed 22. A. elegans. 



Pods ascending 23. A. Brandegei. 



Pods coriaceous or woody. 



Pods stipitate; leaves unifoliolate (JONESIELLA) . . 24. A. asclepiadoides. 

 Pods sessile; leaves pinnate. 



Tall glabrous perennial; calyx-tube not longer than its 



lobes (PHACOPSIS) 25. A. Pattersonii. 



Low caespitose perennials; the calyx-tube longer than its 



lobes (XYLOPHACOS). 



Pods coriaceous, more or less pubescent but not woolly. 

 Herbage appressed silvery-silky. 

 Pods obtuse at base. 



Pods elliptical, straight ..... 26. A. missouriensis. 

 Pods curved or incurved at tip. 



Pods not noticeably veined .... 27. A. Shortianus. 

 Pods transversely veired and finely reticulated 28. A. chamaeluce. 

 Pods tapering to both ends ..... 29. A. amphioxus. 

 Herbage glabrate or villous with loose spreading hairs. 

 Leaves glabrous, at least above. 



Pods sessile 30. A. cibarus. 



Pods stipitate .' . . , , . . 31. A. Beckwithii, 

 Leaves softly villous. 



