CARDUACEAE 

 I. PABRYANA. 



but not tomento^beneath. 



II. ERIOCEPHALA. 



LeTvs dy tomentose on both sides. . 4. C. subniveum. 



Leaves not densely tomentose on both sides. 

 Flowers ochroleucous or white. 



Leaves with very short or no lobes and numerous almost parallel spines along 



the margins, not crisp. 5. C Kelseyi. 



Leaves with deep divisions, often again lobed, crisp, and with the spines point- 



ing in various directions. 

 Leaves white-tomentose beneath. 



Involucre densely arachnoid; bracts all narrowly linear-lanceolate. 

 Heads not nodding, scattered on short branches in the axils of the 



leaves. 6 - C. Hookerianum. 



Heads in a terminal dense cluster, at first nodding. 



7. C. scopulorum. 

 Involucres only slightly arachnoid; outer bracts lanceolate. 



25. C. oreophilum. 

 Leaves glabrous on both sides; heads clustered in an elongate leafy spike. 



8. C. polyphyllum. 

 Flowers purple or pink. 



Involucre densely arachnoid; bracts rarely spinulose-cihate. 



Heads 3.5^4 cm. high, 4-6 cm. broad, not densely clustered; corolla red- 



purple. 9. C. edule. 



Heads 2.5-3 cm. high and about as broad. 



Heads sessile at the end of the stem; bracts linear-subulate; corolla 



purple. 10. C. Macounii. 



Heads scattered; bracts lance-subulate; corolla pink. 



11. C. Tweedyi. 

 Involucres only slightly arachnoid if at all; bracts except the innermost spinu- 



lose-ciliate. 11. C. Eatonii. 



Anthers pubescent. 12. C. hesperium. 



III. LANCEOLATA. 



One species. 13. C. lanceolatum. 



IV. NEOMEXICANA. 



Leaves densely white-tomentose; heads 3.5-6 cm. high, 4-8 cm. broad; bracts strongly 

 squarrose, the outer reflexed. 14. C. neomexicanum. 



Leaves loosely floccose; heads 3-3.5 (rarely 4) cm. high, 3.5-5 cm. broad; bracts spreading 

 only in age. 15. C. nevadense. 



V. CARLINOIDIA. 



Flowers ochroleucous or white; bracts without glutinous ridge. 



Leaves pinnately divided. 16. C. Centaureae. 



Leaves merely sinuately lobed, the upper with broad clasping bases. 



17. C. laterifolium. 

 Flowers red. 



Bracts without glandular ridge; leaves deeply lobed, with lanceolate divisions. 



18. C. vernale. 

 Bracts with glandular ridge; leaves slightly lobed, with broadly triangular lobes. 



19. C. perplexans. 



VI. LEIOCEPHALA. 

 Leaves green on both sides, glabrous or arachnoid beneath. 



Leaves crisp and very spiny; involucral bracts very spiny, the outer ones as long as 



the inner; corollas rose or pink. 20. C. Eatoni. 



Leaves almost flat, with weak spines; involucral bracts well imbricate, the outer 



ones short and with short spines. 21. C. clavatum. 



Leaves tomentose beneath; involucral bracts with strong flat spines. 



39. C. griseum. 

 VII. FOLIOSA. 



Plant acaulescent or nearly so; heads clustered. 22. C. acaulescens. 



Plant distinctly caulescent. 



Inner bracts with scarcely dilated, not erose linear-lanceolate tips. 

 Heads 3.5-5 cm. high. 



Leaves deeply pinnatifld, with strong spines. 23. C coloradense. 



Leaves nearly entire, spinulose-ciliate. 24. C. Butleri. 



Heads 2-3.5 cm. high. 



Leaves green, distinctly decurrent. 



Lobes of the leaves lanceolate or triangular. 33. C. calcareum. 



Lobes of the leaves semi-orbicular. 34. C. lactucinum. 



Leaves more or less tomentose beneath, scarcely decurrent. 



Bracts broad and short, with flat spines. 35. C. spathulatum. 



