172 COMPOSITE. (COMPOSITE FAMILY.) 



50, white or purple changing to white: akenes slender and nearly terete, 8 to 

 10-nerved or striate: pappus double ; the outer subulate and conspicuous. 



17. E. canus, Gray. Silvery appressed pubescence obviously strigulose 

 under a lens, that of the involucre loose and spreading : stems 4 to 9 inches 

 high, leafy : linear cauline leaves gradually diminishing upward ; radical 

 spatulate-lanceolate or narrower : head 4 lines high : rays narrow, 3 lines 

 long : akenes glabrous. — PI. Fendl. 67. N. New Mexico and Colorado ; also 

 *m the Platte in Wyoming. 



•*-*■ ++ ++ Either low or comparatively tall, leafy -stemmed or someichat scape-like: 



akenes compressed, 2 or 3-nerved. 



= Leaves all narrowly linear to jilt form, the broadest not over a line wide: 



involucre 3 or 4 lines high, of equal bracts. 



18. E. OChroleucus, Nutt. Low, a span or two high, somewhat cespi- 

 tose, from pubescent to glabrate : stems usually simple, naked above and 

 mostly monocephalous : leaves rather rigid, the radical 2 or 3 inches long : 

 involucre hirsute-pubescent : rays 40 to 60, " ochroleucous," white or purplish : 

 outer pappus setulose. — Gravelly soil, N. Wyoming and Montana to Idaho. 



= = Leaves from narrowly linear to oblong. 



a. Stems naked above, mostly simple and monocephalous, a span or two high : 



pappus simple. 



19. E. Eatoni, Gray. Stems several from the crown of a strong tap 

 root, slender and weak, diffuse, 3 to 9 inches long, simple or with 2 or 3 

 monocephalous branches: leaves all linear, thickish, minutelv pubescent; 

 radical about 2 inches long and the broadest 2 lines wide : heads only 3 lines 

 high : bracts of the sparsely hirsute involucre little unequal : rays seldom 

 over 20, at most 3 lines long, white or purplish. — Proc. Am. Acad, xvi 91. 

 E. ochroleucus, Eaton, Bot. King Exp. 152. Mountains of Colorado, Wyo- 

 ming, and Utah. 



b. Stems more leafy and disposed to branch, but sometimes monocephalous: 

 pubescence cinereous : outer pappus setulose, sometimes obscure or none. 



20. E. CSespitOSUS, Xutt. Low, a span to rarely a foot high, many- 

 stemmed and ascending or spreading from a stout caudex, from cinereous to 

 canescent with dense and fine short pubescence : stems of smaller plants 

 monocephalous : radical leaves spatulate to lanceolate, and cauline lanceolate- 

 oblong to linear, ^ to 2 inches long : heads short-peduncled, 3 or 4 lines high : 

 bracts of the involucre rather unequal : rays 40 or 50, linear, 3 or 4 lines long, 

 white, sometimes tinged with rose-color. — From the Saskatchewan to New 

 Mexico and westward. 



21. E. COrymbosus, Xutt. Taller, often afoot or two high, erect from 

 creeping rootstocks, soft-cinereous with mostly spreading short pubescence : 

 radical leaves narrow-lanceolate or spatulate-lanceolate, largest 3 or 4 inches 

 long and 3 or 4 lines wide, 3-nerved ; cauline linear and narrow : heads some- 

 times solitary, usually several and corymboscly disposed on short slender pedun- 

 cles : involucre 3 lines high, canescently pubescent: rays 30 to 50, mostly 

 narrow and 3 to 5 lines long, blue or violet, apparently sometimes white. — 

 Mountains of Montana to those of Washington and California. 



