242 CARDUACEAE 



X. Radulini. 

 Upper part of the stem and the involucres long-villous. 1.5. A. Richardsonii. 



Upper part of the stem and involucres short-pubescent. 16. A. meritus. 



XI. Andini. 



Stems decumbent or ascending, about 1 dm. high; leaves glabrate. 



17. A. andinus. 

 Stems erect, about 3 dm. high; leaves finely villous. 18. A. Williamsii. 



XII. Grisei. 



Leaves rather copiously and permanently appressed-liirsutulous. 



Inflorescence falsely racemose; lower leaves triple-nerved. 40. .4. subracemosus. 



Inflorescence corymbiform or paniculate; leaves all 1-nerved. 



Plant :3-4 dm. liigh; stem retrorse-hirsute below. 19. A. subgriseus. 



Plant 1-1.5 dm. high; hairs of the stem not retrorse. 20. A. griseolus. 



Leaves sparingly strigose and glabrate in age, or perfectly glabrous, except the hispidu- 

 lous-ciliate margins. 

 Bracts with a green tip and midvoLn. 



Stem stout; leaves oblanceolate, the lower often triple-nerved. 



01. .4. Underwoodii. 

 Stem slender; leaves narrowly Unear-oblanceolate or linear, 1-nerved. 



64. A. Nelsonii. 

 Outer bracts green almost throughout. 21. A. violaceus. 



XIII. MULTIFLORI. 



Inflorescence very leafy, not corymbiform. 



Pubescence of the stem spreading or reflexed, hirsutulous. 



Heads less than 5 mm. liigh. 22. A. exiguus. 



Heads 6-8 nun. high. 23. A. crassulus. 



Pubescence of the stem appressed or ascending. 



Bracts very unlike in length, well imbricate, the outer much shorter; heads race- 

 mosely arranged, each at the end of a short leafy branch (except in no. 25) . 

 Bracts narrowly oblanceolate, the inner especially acutish; heads less than 5 

 mm. high. 

 Stem much branched ; heads racemosely disposed on the more or less diverg- 

 ing branches. 24. A. muUiflorus. 

 Stem simple below; heads few at the ends of the erect branches. 



25. ^4. stricticaulis. 

 Bracts broadly oblanceolate or the outer spatulate, very obtuse; heads over 

 5 mm. high. 26. ,4. polycephalus. 



Bracts almost equal in length or the outer .sometimes longer; heads few or solitary 

 at the ends of the main l^ranches. 

 Bracts thick, very squarrose, the outer spatulate, rounded at the apex; leaves 



tliick, densely strigose. 27. A. commulatus. 



Bracts tliin, sUghtly squarrose, oblanceolate, acute; leaves sparingly strigose, 

 in age often glabrate. 28. A. falcatus. 



Inflorescence less leafy, corymbiform; leaves glabrous, merely hispid-ciliolate; disk 6-S 

 mm. wide; stem slender. 

 Stem glabrous. 29. A. dcnudalus. 



Stem puberulent. 67. A. Hallii. 



XIV. S.\GITTIFOLII. 



Basal leaf-blades cordate or broadly ovate; upper stem-leaves lanceolate; achenes gla- 

 brous. 

 Petioles, midribs, and usually also the stem pubescent with long white hairs. 



30. A. Wilsonii. 

 Plant glabrous or sparingly short-pubescent. 31. A. Lindlei/anus. 



Basal leaf-blades lanceolate; upper stem-leaves narrowly lanceolate or those of the inflor- 

 escence lance-Unear. 

 Heads few; involucres 8-9 mm. high; rays about 15 mm. long; achenes glabrous. 



32. A. MacCallae. 

 Heads numerous; involucres 5-6 mm. liigh; rays 8-10 mm. long; achenes hispidulous- 

 strigose. 33. A. Butleri. 



XV. L.\EVES. 



Bracts much shorter than the disk. 34. .4. brevibracteatus. 



Bracts about equalhng the disk or only slightly shorter. 

 Leaves merely scabrous-ciUate. 



Green tips of the bracts broadly rhombic; leaves of the branches much reduced. 



35. .4. laevis. 



Green tips of the bracts narrowly rhombic or rhombic-oblanceolate; leaves of 

 the branches gradually but not conspicuously reduced. 

 Stem-leaves lanceolate or Unear-lanceolate, auricled-clasping. 



36. .4. Geycri. 

 Stem-leaves narrowly linear, not auricled. 37. A. subsalignus. 



Leaves decidedly long-ciUate; bracts with oblong green tips. 38. A. Scribneri. 



XVI. PORTERIANI. 



One species. 39. A. Porieri. 



XVII. Salicifolii. 



Inflorescence falsely racemose; leaves linear to oblanceolate; leaves triple-nerved. 



40. A. subracemosus. 



