852 CARDUACEAE 



high and about as broad; bracts linear, acute, rather sparingly hirsute. Sandy 

 soil in canons: Colo. Submont. Au. 



15. C. barbata Rydb. Stems about 3 dm. high, more or less tinged with 

 purplish or red, hirsute with long white hairs; leaves sessile, 3-5 cm. long, long- 

 hirsute and somewhat resinous-granulif erous ; heads subsessile; involucres 1 cm. 

 high and 12-15 mm. broad; bracts linear, acute; ligules about 7 mm. long. Sandy 

 plains: Ida. Jl. 



16. C. Butleri Rydb. Stem decumbent at the base or erect, grayish-his- 

 pidulous and slightly hirsute; leaves 1-3 cm. long, obtuse or apiculate, gray- 

 ish-hirsute with short hairs; heads peduncled; involucres 8 mm. high, 10-15 mm. 

 broad; bracts linear, acute; ligules about 8 mm. long. Plains and hills: Mont. 



-Utah. Plain. Au-O. 



17. C. pumila Greene. Stems decumbent at the base; leaves oblanceolate, 

 1-3 cm. long, mostly petioled, hirsute but not viscid; involucres about 8 mm. 

 high and 1 cm. broad; bracts linear, hirsute but not viscid; ligules about 6 mm. 

 long. Canons and mountain sides: Neb. Colo. Ida. Plain Subalp. Je-S. 



18. C. columbiana Greene. Stems ascending or decumbent at the base; 

 leaves oblanceolate or the uppermost linear-lanceolate, 2-3 cm. long, hispidulons 

 on both sides, scarcely at all resinous; heads corymbose; involucres 8 mm. high. 

 Hills and sandy places: B.C. Mont. Ore. Je-S. 



19. C. grandis Rydb. Stems about 3 dm. high; leaves spatulate or ob- 

 lanceolate, 3-5 cm. long; involucres 8 mm. high; ligules about 1 cm. long. Sandy 

 places: Mont. Wyo. Plain Submont. Je-Au. 



20. C. resinolens A. Nels. Stems 2-4 dm. high, sparingly hirsute and 

 resinous-granulif erous ; leaves hirsute and resinous-granulif erous, hispid-ciliate, 

 the lower oblanceolate, the upper oblong or oblong-oblanceolate, sessile, 3-5 cm. 

 long, obtuse or apiculate; heads crowded, corymbose; involucres 1 cm. high, 

 1-1 5 cm. broad. Sandy soil: Mont. Colo. Ariz. Utah. Submont. Mont. 

 Jl-S. 



21. C. fulcrata Greene. Stem 2-6 dm. high, hirsute, hispidulous and 

 resinous-granulif erous ; leaves oblong, elliptic or the lower oblanceolate, hirsute, 

 hispidulous and granulif erous ; heads corymbose, sessile; involucres 8-9 mm. high. 

 Mountains: N.M. Tex. Wyo. Submont. Mont. Jl-S. 



22. C. horrida Rydb. Stems 2-3 dm. high, hirsutulous and hispid; leaves 

 obovate, broadly oblanceolate, or oblong; heads corymbose, peduncled, about 

 8 mm. high; disk 1 cm. or less wide; bracts sparingly strigose-hirsute. Hills: 

 Neb. Wyo. N.M. Tex. Plain Son. Jl-S. 



23. C. viscida (A. Gray) Greene. Stem 1-3 dm. high, resinous-granulif erous 

 and hispidulous; lower leaves spatulate and petioled, the upper obovate, elliptic, 

 or ovate, sessile, 1-2 cm. long; heads few or solitary; involucres 8 mm. high and 

 10 mm. wide; bracts resinous-granulif erous and hispidulous. C. villosa viscida A. 

 Gray. Mountains and dry ledges: Colo. Tex. Ariz. Plain Mont. My-N. 



24. C. asprella Greene. Stem erect, 2-4 dm. high, hispidulous and sparingly 

 hirsute, simple up to the inflorescence; head corymbose; involucres 7-8 mm. high 

 and broad. C. compacta Greene. C. arida A. Nels. Dry hills and mountains: 

 Mont. N.M. Ariz. Submont. Subalp. Jl-S. 



25. C. hispida (Hook.) DC. Stems 2-3 dm. high, hirsute and resinous- 

 granulif erous; lower leaves oblanceolate and petioled, the upper lanceolate, 

 sessile, 1-3 cm. long; heads corymbose and peduncled; involucres 7-8 mm. high 

 and 8-12 mm. wide. C. villosa hispida A. Gray. Sandy river valleys: Sask. 

 N.M. Ariz. Calif. B.C. Plain Submont. Je-Au. 



26. C. stenophylla (A. Gray) Greene. Perennial, with cespitose caudex; 

 stem 2-4 dm. high, very hispid, stiff; leaves 2-3 cm. long, spreading, early de- 

 ciduous, hispid and resinous-granulif erous, the hairs with pustulate bases; heads 

 subtended by a few narrow leaves; involucres 8 mm. high and 1 cm. broad; bracts 

 granulif ero us and sparingly hirsute. C. villosa stenophylla A. Gray. Dry plains: 

 Tex. Colo. Ark. Plain. Au-S. 



