THISTLE FAMILY 851 



the inner •nith purplish margins; ligules golden yellow, 5-6 mm. long, 1-1.5 mm. 

 wide. Hills: s Utah. Son. My. 



3. C. alpicola Rydb. Stems silky-villoiis, numerous; leaves oblanceolate, 

 about 3 cm. long, nearly all petioled, white-silky, strigose or the pubescence more 

 spreading on the petioles; bracts linear-lanceolate, strigose or silky, acute; ligules 

 about S mm. long and 2 mm. wide. C. Cooperi A. Nels. C. -pumila Coult. & 

 Nels., not Greene. High peaks: Colo. — Wyo. Subalp. — Alp. Jl-Au. 



4. C. foliosa Nutt. Stem 3-6 dm. high, very leafy, canescent, strigose and 

 hirsute; lower leaves oblanceolate, acute, 3-5 cm. long, white silky-strigose on 

 both sides, subsessile; heads subtended by linear bract-like leaves, about 1 cm. 

 high; bracts linear, acute, strigose. Sandy soil: Minn. — Kans. — Utah — Wash. 

 Plain — Subniont. Jl-Au. 



5. C. caudata Rydb. Stems many, erect, hirsute with long white hairs; 

 lower leaves oblanceolate, silky-strigose on both sides, 3-5 cm. long; heads con- 

 gested in small clusters at the end of the branches; bracts linear-lanceolate, hir- 

 sute-strigose ; ligules bright yellow, about 12 mm. long. Hills and moimtains: 

 Colo. Submont. — Mont. Jl-Au. 



6. C. amplifolia Rydb. Stem 3-5 dm. high, often branched, pubescent 

 and sparingly hirsute; lower leaves spatulate, strigose, obtuse or slightly mucron- 

 ate, the uppermost cordate or truncate at the base, 3-4 cm. long, 12-15 mm. 

 wide; inflorescence corymbiform; bracts hirsute-strigose, linear-lanceolate, acute; 

 ligules about 12 mm. long. Mountains: Colo. — Wyo. Submont. Jl-Au. 



7. C. imbricata A. Nels. Stems 3-4 dm. high, subcanescent and with some 

 long hairs; leaves niunerous, the lower oblanceolate or spatulate, petioled, the 

 upper broadly oblong or oblong-oblanceolate, sessile and mostly obtuse or apicu- 

 late, graj-ish hirsutulous; involucres 8-10 mm. high; bracts lance-linear, hirsute- 

 strigose. Mountains: Colo. — Utah — Mont. Submont. Jl. 



8. C. depressa Rydb. Stems intricately branched; leaves seldom over 1 

 cm. long, obovate or spatulate, the lower short-petioled, the upper sessile, densely 

 silky-strigose canescent; involucres about 7 mm. high and 1 cm. broad; bracts 

 linear, acute, puberulent-strigose. Geyser formations: Mont. — Wyo. Mont. 

 Au. 



9. C. pedunculata Greene. Stems short, decmnbent, about 2 dm. high, 

 strigose-canescent; leaves oblanceolate, silvery canescent, 2-3 cm. long; heads 

 solitary, on peduncles 2-8 cm. long; involucres 8 mm. high, 1-1.5 cm. broad; 

 bracts linear, acute, strigose-canescent. Dry hillsides: Colo. Submont. Jl. 



10. C. mollis Nutt. Stems decimibent to erect, 2^ dm. high, finely stri- 

 gose-canescent; leaves spatulate or oblanceolate, obtuse or apiculate, or the 

 upper oblong and more acutish, 2-4 cm. long; heads corymbose, peduncled; 

 involucres about 8 mm. high and as wde; bracts Unear, acute. Sandy places: 

 Wash.— Utah— Wyo.— Mont. Jl-Au. 



11. C. villosa (Pursh.) Nutt. Stem 2-5 dm. high, strigose and more or less 

 hirsute; leaves 2-4 cm. long, obovate, elliptic or oblong, appressed silky, hirsute- 

 ciliate, usually sessile; heads peduncled, sometimes subtended by a small leaf; 

 involucres about 1 cm. high. Dry hills: Sask. — Minn. — Tex. — N.M. — Ida. 

 Plain — Mont. Jl-S. 



12. C. hirsutissima Greene. Stem 1-3 dm. high, densely long-hirsute as 

 well as hirsutulous; leaves oblanceolate, somewhat spreading, the lower short- 

 jDetioled, the upper sessile, densely grayish-strigose ; heads fastigiate-corymbose ; 

 involucres 8 mm. high. Sandy soU: Sask. — N.D. — N.M. — Ariz. Plain — Sub- 

 mont. Je-Au. 



13. C. Bakeri Greene. Stems 2-4 dm. high, often purplish, strigose and 

 only sparingly hirsute; leaves mostly acute, strigose, only slightly resinous- 

 granuliferous; heads few, peduncled; involucres about 8 mm. high; bracts often 

 purpUsh-margined. Hills: Wyo. — Ida. — N.M. — Utah. Submont. — Mont. Jl-Au. 



14. C. floribunda Greene. Stem about 3 dm. high, sparingly strigose and 

 with a few long spreading hairs; heads paniculate, small; involucres 7-8 mm. 



