676 



CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



Bracts appressed except at the very tips; rays 

 narrow; pappus usually double. 



Rays white; pappus uniseriate 32. E. rusbyi. 



Rays lavender to deep purple; pappus double. 

 Upper cauline leaves reduced, linear-lance- 

 olate; none of the leaves 3-nerved; pe- 

 duncles long, erect. 



Leaves canescent 33 . E. deminutus. 



Leaves glabrous or nearly so, or merely 

 ciliate, never canescent. 

 Involucres glandular-puberulent, spar- 

 ingly if at all hairy. 

 Stern with long white hairs through- 

 out; lower leaves hairy 34. E. viscidus. 



Stem glabrous below, glandular-pu- 

 berulent above ; leaves glabrous. 35. E. smithii. 

 Involucres densely hirsute, villous, or 

 strigose. 

 Stems villous throughout; plants low, 



usually 20 cm. high or less 36. E. pecosensis. 



Stems glabrous below, usually much 

 more than 20 cm. high. 

 Disk more than 15 mm. broad; 



heads solitary or very few 37. E. formosissimus. 



Disk less than 12 mm. broad; heads 



more numerous 38. E. glabellus. 



Upper cauline leaves ample, not much 

 smaller than the lower, lanceolate to 

 ovate; lower leaves 3-nerved; peduncles 

 short, ascending. 

 Leaves glabrous, smooth to the touch, 

 sometimes ciliate. 

 Basal leaves broadly obovate-spatulate, 

 often denticulate; cauline leaves 

 distant, shorter than the inter- 

 nodes, not ciliate 39. E. superbus. 



Basal leaves oblanceolate, en the; cau- 

 line leaves more numerous, longer 

 than the internodes, usually ciliate. 

 Bracts glandular-puberulent, not at 



all hirsute 40. E. macranthus. 



Bracts hirsute or villous 41 . E. speciosus. 



Leaves more or less pubescent, rough to 

 the touch. 



Leaves densely canescent, grayish 42. E. subtrinerv'ts. 



Leaves not canescent, green. 

 Stems hirsute throughout. 

 Upper leaves ovate to oblong, 



mostly obtuse 43. E. platyphyllus. 



Upper leaves lanceolate, very 



acute 44. E. rudis. 



Stems not hirsute, at least below. 

 LTpper leaves broadly lanceolate, 



scaberulous;stemspuberulent.45. E. semirasus. 



