COMPOSITAE (COMPOSITE FAMILY; 



801 



Plant cinereous-pubescent, witli small leaves (5 cm. or 



less long); heads (5 mm. high 85. A. amethysUnua. 



riant green and essentially glabrous ; leaves aiyl heads 



larger; bracts herbaceous, the outer often foliaceous 46. A. novi-belgii. 

 Tips of bracts ascending, not recurved. 



Bracts linear-oblong or lanceolate, firm, with dilated 

 herbaceous tips ; rays deep blue or violet. 

 Leaves conspicuously clasi)ing, the auricles generally 



meeting around the stem 18. A. paten a. 



Leaves shghtly or inconspicuously clasping . . . 31. A. concinnus. 

 Bracts linear-attenuate, thin, with slender green or col- 

 ored tips ; rays white or lavender . . . . 42, A. paniculatua. 

 N. Bracts of the involucre essentially equal, only the very outer- 

 most sometimes broader and shorter. 

 Tips of bracts acute (not attenuate), recurved-spreading or 



squarrose 46. ^. novi-helgU. 



Tips of bracts (except occasional outer foliaceous ones) long- 

 attenuate, ascending, not recurved. 

 Stem slender, glabrous or villous ; leaves long-lanceolate ; 



involucre 5-S mm. high 45. ^. longifohua. 



Stem stout, glabrous or harshly pubescent; leaves lanceo- 

 late to. narrowly rhombic-obovate ; involucre 7-l'2 mm. 



jjj„}j 49. A. puniceus. 



K. Stem-leaves narrowed or rounded or cordate at base, but not 

 clasping P. 

 P. Leaves silvery-silky on both faces, entire. 



Heads soUtary or few at the tips of the branches; achenes 



smooth : \^' i- >^ericeus. 



Heads in a wand-like raceme ; achenes silky . •„ • ^ • ^T- ^- concoior. 

 P. Leaves green, not silvery-silky, sometimes pilose or villous Q. 

 Q. Involucre glandular-viscid ; rays violet R. 

 B. Basal leaves petioled, much larger than the caulme. 



Basal leaves ovate or ovate-oblong, on nearly naked peti- „ ^ „ 



oles ; involucral bracts erect 1. A. Herveyx. 



Basal leaves narrower, on margined petioles ; involucre 

 squarrose. . 



Tall; basal leaves spatulate- to lance-oblong; involucre 



1-1.5 cm. high, very glandular 8. ^. spectabilis. 



Low ; basal leaves lanceolate ; involucre mostly shorter, 



barely glandular . 9. A. surculosus. 



B. Basal and stem-leaves uniform, linear to oblong, the lower 

 not conspicuously petioled. 

 Leaves firm, linear- to lance-oblong, entire, blunt or 

 acutish. . 



Stem hispid; uppermost leaves passing mto mvolucral 



bracts . \2. A. grand ijf or us. 



Stem glandular-puberiilent ; uppermost leaves and invo- 



lucral bracts distinct If. ^. oblongt/ohus. 



Leaves thin, lanceolate, acuminate, subentire to serrate . 15. A. modestus. 

 Q. Involucre not glandular S. . 



S. Basal leaves with definite margined petioles. 

 Involucral bracts oblong, coriaceous. 

 Leaves entire or slightly dentate. 

 Bracts strongly ciliate ; involucre turbinate-hemispher- 



jgjjj ^ 9. ^. surculosua. 



Bractsnot ciliate, nearly or quite glabrous; involucre 



slender-turbinate 10. A gracths. 



Leaves serrate 11. ^. radula. 



Involucral bracts linear or linear-subulate, thin . . . 4:1. A. tardtflorua. 

 S. None of the leaves definitely petioled, or the lower incon- 

 spicuously so T. 

 T> Stem-leaves linear U. , .. , , r. * 



U. Stem glabrous or glabrate, or only shghtly pubescent 

 above V. 

 V. Involucre 5 mm. or less high W. 

 W. Bracts with definite firm subulate tips. 



Involucre hemispherical or camjianulate, as broad 



as hi^-h 83. ^. ertcoides. 



Involucre^'turbinate, only 2-3 mm. broad . . 34. A.depauperatu^. 

 ■ W. Bracts without firm subulate tips X. 



X. Bracts with conspicuous elliptic or subrhombic 



nfadrtemiinating minutely foliose hranchlets 38. A.dumoms. 

 Heads paniculate or if few on leafy (not minutely ,-^,vv.;;«. 



foliose-bracteolate) branchlets ... 43. A. sahatohns 

 X Bracts attenuate, without conspicuous dilated tips. 

 Kays white (or lavender-tinged). 

 Branches ascending-paniculate ; heads in ra 

 cemo-paniculate clusters. 



GRAY'S MANUAL — 51 



