COMPOSITAE (COMPOSITE FAMILY) 



523 



RAYS CONSPICUOUS (much surpassing the disk) 



PERENNIALS 



Leaves entire or merely toothed. 



Stems usually more than 3 dm. high, simple below, solitary 



from the ends of distinct (sometimes branched) root-stocks. 



Involucre with spreading or reflexed bracts; rays rather 



broad; pappus simple. 

 Involucre glabrous or glandular . . . . .I.E. salsuginosus 



Involucre woolly, or hirsute and viscidulous. 



Involucre very woolly . . . . . . . 2. E. elatior. 



Involucre viscidulous and moderately hirsute . . 3. E. Coulter! 

 Involucre with mostly appressed bracts; rays numerous and 



narrow; pappus double. 

 Rather equably leafy, the upper stem leaves not greatly 



reduced. 

 Leaves few, short, and distant, broadly obovate to 



ovate or broadly oblong . . . . . . 4. E. superbug. 



Leaves more numerous, oblanceolate to ovate and oblong. 



Bracts glabrate, obscurely glandular . . . 5. E. macranthus. 

 Bracts more or less hirsute. 



Herbage nearly or quite glabrous . . . 6. E. speciosus. 



Herbage clearly pubescent . . . . . 7. E. subtrinervis. 



Quite inequably leafy, the upper stem leaves greatly re- 

 duced in size. 



Pale green and apparently glabrate, but under a lens 

 minutely rough-hirsute ...... 



Dark green and distinctly pubescent, often viscidulous, 

 especially above ....... 



Stems usually less than 3 dm. high (mostly 1-2 dm.), either 



branched near the base or somewhat caespitose. 

 Stems mostly simple and monocephalous. 



Stems leafy below, either scapiform or with greatly re- 

 duced leaves above; heads mostly solitary on the 

 bracted or naked peduncle. 

 Leaves spatulate or oblanceolate to linear. 

 Involucre woolly. 



Wool of involucre blue-black; rays white 

 Wool of involucre mostly white; rays violet or 

 whitish ........ 



Involucre hispid or minutely hirsute. 

 Rays not yellow. 

 Rays white. 



Bracts hispid-ciliate ..... 19. E. Engelmannii. 



Bracts appressed-hirsute . . . . 20. E. Eatonii. 



Rays blue, violet, or purple. 



Hispid-ciliate throughout .... 21. E. poliospermus. 



Pubescence not hispid, mostly short and ap- 

 pressed. 



Rays violet 18. E. ursinus. 



Rays pale purple 17. E. radicatus. 



Rays yellow 22. E. luteus. 



Leaves obovate to short-oblong. 



Plant green and glabrate 12. E. Garrettii. 



Plant pale-canescent ....... 13. E. tener. 



Stems leafy throughout. 



Leaves all broad, obovate to short-oblong . . . 14. E. nauseosus. 

 Leaves narrowly lanceolate to linear. 



Involucre glabrous but pruinose-glandular; foliage 



glabrous or nearly so . . . . . . 15. E. leiomeris. 



Involucre hirsute or pubescent. 



Leaves glandular-scabrous and hirsute ... 16. E. glandulosus. 

 Leaves not glandular. 

 Rays not yellow. 



Rays purple or violet. 

 Leaves subglabrous. 



Plants low (4-10 cm.); pubescence spread- 

 ing . . . . . . . 17. E. radicatus. 



Plants taller (8-16 cm.); pubescence ap- 

 pressed . . . . . . 18. E. ursjnus. 



Leaves hispid-hirsute 21. E. poliospermus. 



Rays white. 



Bracts hispid-ciliate . . . . . 19. E. Engelmannii. 

 Bracts appressed-hirsute . . . . 20. E. Eatonii. 



Rays yellow 22. E. luteus. 



Stems more or less branched and with few-several heads. 

 Rays white. 



Leaves 1 -nerved. 



Herbage minutely hirsute. 



Bracts hispid-ciliate 19. E. Engelmaaaii. 



8. E. asper. 



9. E. formosissimus. 



10. E. melanocephalus. 



11. E. uniflorus. 



