400 CARDUACEAE. 



v. PUI.CIIEI.I.I. 



Leaves not whitc-tomentose beneath. 



Leaves sparingly floccose when young, or glabrate. i8. C. truncalus. 



Leaves glabrous, the lower twice pinnate. 19. C. bipimiatus. 



Leaves white-tomentose beneath. 20. C. pulchellus. 



VL Undulati. 



Flowers ochroleucous ; bracts very viscid, with broad glandular dorsal ridges. 

 Tips of the inner bracts more or less dilated and crisp ; involucre of the ter- 

 minal head 4-5 cm. in diameter. 21. C. plattensis. 

 Tips of the inner bracts linear-lanceolate, neither dilated nor crisp ; involucres 

 usually 3 cm. wide or less. 22. C. Tracyi. 

 Flowers rose or purple, rarely white ; glandular ridge not so prominent. 

 Involucres less than 3 cm. wide. 



Spines of the middle bracts 5-10 mm. long, erect or ascending. 



22,. C. canescens. 

 Spines of the middle bracts 5 mm. or less long, weak and spreading. 



Leaves entire or slightly lobed. 24. C. oblanceolatus. 



Leaves pinnately divided or deeply lobed. 



Leaves deeply pinnatifid with narrow, linear-lanceolate lobes ; plant 



often yellowish. 25. C. Flodmanii. 



Leaves with triangular or ovate-lanceolate lobes. 



Bracts with a very inconspicuous glandular ridge, not at all viscid. 



26. floccosus. 



Bracts with a conspicuous glandular ridge, surrounded by a viscid area, 



27. C. undulatus. 

 Involucres 4-6 cm. in diameter. 



Spines of the involucral bracts scarcely over 5 mm. long ; leaves very broad. 



28. C. megacephalus. 

 Spines of the involucres i cm. long; leaves narrow. 29. C. ochrocentrus. 



VII. Altissimi. 



One species. 30. C. filipendulus. 



VIII. Arvenses. 



One species. • 31. C. arvensis. 



IX. Neo-mexicaxi. 

 One species. 32. C. neo-mexicanns. 



1. Carduus Parryi (A. Gray) Greene. (Cnicus Parryi A. Gray) In the 

 mountains of Colo., Utah and N. M. — Alt. 5000-11,000 ft. — Marshall Pass; 

 La Veta; along the Uncompahgre River, near Ouray; Steele Cafion, Villa 

 Grove; Redclifife; Marshall Pass; Echo Creek, near La Veta; Veta Pass; 

 near Pagosa Peak ; Boulder ; near Empire ; Twin Lakes. 



2. Carduus Osterhoutii Rydb. In the mountains of Colo. — Redclifife ; Ten- 

 nessee Pass. 



3. Carduus Hookerianus (Nutt.) Heller. {Cnicus Hookcrianus A. Gray) 

 In the mountains from Alb. and B. C. to Colo. — Alt. 11,000-12,000 ft. — Bert- 

 houd Pass. 



4. Carduus araneosus Osterhout. Mountains of Colo. — Redclifife. 



5. Carduus oreophilus Rydb. In wooded valleys of Colo. — Alt. 6000-12,000 

 ft. — Banks of Larimer Co.; Silver Plume; Georgetown; Pagosa Springs; 

 Steamboat Springs; Boreas; Garland. 



6. Carduus scopulorum Greene. {Cnicus eriocephalus A. Gray) In the 

 mountains of Colo. — Alt. 9500-12,000 ft. — Ward; Mt. Harvard; head of 

 Beaver Creek ; Ruxton Dell ; Mt. Baldy, Pike's Peak ; Cameron Pass ; Bert- 

 houd Pass. 



