898 CARDUACEAE 



III. COMPOSITT. 



Leaves divided into linear or spatulate divisions; plant with a cespitose caudex. 

 Leaves pinnately divided. 



Heads radiate; leaf segments rather distant; peduncles 5-20 cm. long. 



15. E. pinnatisectus. 

 Heads discoid; leaf segments crowded; peduncles 2-5 cm. long. 



16. E. mancus. 

 Leaves once to thrice ternately divided. 



Leaf-blades twice or thrice ternate. 17. E. compositus. 



Leaf-blades cuneate, ternately or pedate-quinnately cleft at the apex; divisions 



spatulate. 

 Disk 10-15 mm. broad; bracts linear-subulate, scarcely scarious-margined; 



lobes of the leaves spatulate. 18. E. trifidus. 



Disk 7-10 mm. broad; bracts linear-lanceolate, scarious-margined; lobes of 



the leaves linear. 19. E. pedatus. 



Leaves flabelliform, lobed or twice 3-cleft at the apex; plant with a creeping rootstock. 



20. E. flabellifolius. 



IV. RADICATI. 

 Head radiate. 



Involucre glandular-puberulent or glabrate, not hirsute. 



Stem and leaves glabrous or nearly so; involucres less than 12 mm. broad. 

 Basal leaves linear-oblanceolate. 21. E. leiomerus. 



Basal leaves spatulate. 22. E. spathulifolius. 



Stem and leaves pubescent; involucres 12-15 mm. wide. 



Stem and leaves hirsute. 63. E. viscidus. 



Stem strigose; leaves puberulent, especially on the margins. 



23. E. controversies. 



Involucre more or less hirsute or strigose, in some also slightly glandular-puberulent. 

 Leaves and stem glandular scabrous as well as hirsute. 24. E. glandulosus. 

 Leaves and stem hirsute or strigose, rarely glandular. 



Stem 1 dm. or more high, appressed-pubescent ; disk over 1 dm. high; branches 



of the caudex or rootstock rather slender, often purplish. 

 Leaves narrowly linear-oblanceolate, 1-3 mm. wide, strigose. 

 Involucral bracts with appressed pubescence; rays purple. 



25. E. gracilis. 



Involucral bracts with spreading pubescence. 26. E. Engelmannii. 

 Rays white; bracts narrowly Linear. 

 Rays usually purplish; bracts lance-linear. 

 Leaves oblanceolate to linear-oblanceolate, 3-8 mm. wide, glabrous above, 



except the margins. 27. E. ursinus. 



Stem 4-7 cm. high; disk less than 1 cm. wide; caudex and its branches stout 



and short, not purplish. 

 Leaves linear-oblanceolate to spatulate. 

 Stem with appressed hairs, or glabrate. 



Leaves and stem glabrous or nearly so; stem almost leafless. 



28. E. Evermannil. 

 Leaves and stem distinctly strigose, the latter with several leaves. 



29. E. Peasei. 

 Stem with more or less spreading hairs. 



Stems decumbent or ascending ; leaves spreading, either softly hairy 



or glabrate in age. 



Pappus double; inner pappus of 10-12 bristles, 2 mm. long; 

 outer pappus of small squamellae; rays white. 



30. E. radicatus. 

 Pappus simple or nearly so, consisting of many bristles, 3 mm. 



long; rays purple. 31. E. vetensis. 



Stems and leaves almost erect; the latter coarsely hirsute. 



Basal leaves narrowly linear-oblanceolate ; stem-leaves linear. 



32. E. nanus. 

 Basal leaves narrowly spatulate; stem-leaves oblanceolate. 



38. E. condensatus. 



Leaves linear-filiform. 33. E. nematophyllus. 



Heads discoid; leaves narrowly linear. 34. E. Bloomeri. 



V. PUMILT. 



Pubescence of rather long hairs ; branches of the stem almost erect. 

 Heads radiate. 



Stems over 1 dm. high, when well developed, with more than one head each. 

 Ray-flowers white. 



Outer pappus of small inconspicuous bristles; plant copiously hairy. 



35. E. pumilus. 



Outer pappus of broad squamellae; plant sparingly hairy. 

 , 36. E. Brandcgci. 



Ray-flowers blue or purplish; outer pappus conspicuous and squamellate. 



37. E. concinnus. 

 Stems usually less than 1 dm. high and usually monocephalous. 



Leaves spatulate. 38. E. condensatus. 



Leaves narrowly linear-oblanceolate. 32. E. nanus. 



Heads discoid. 39. E. aphanactis. 



Pubescence very short; branches of the stems spreading. 72. E. Wootonii. 



