COMPOS1TAE (COMPOSITE FAMILY) 



801 



35. A. amethystinus. 

 46. A. novi-belgii. 



18. A. patens. 

 81. A. concinnus. 



42. A. paniculatus. 

 46. A. nom-belgii. 



45. A. longifoUus. 

 49. A.puniceus. 



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



less long) ; heads 6 mm. high 



Plant green and essentially glabrous ; leaves and heads 

 larger ; bracts herbaceous, the outer often foliaceous 

 Tips of bracts ascending, not recurved. 

 Bracts linear-oblong or lanceolate, firm, with dilated 



herbaceous tips ; rays deep blue or violet. 

 Leaves conspicuously clasping, the auricles generally 



meeting around the stem 



Leaves slightly or inconspicuously clasping . 

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

 ored tips ; rays white or lavender .... 

 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 



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

 attenuate, ascending, not recurved. 

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



involucre 5-8 mm. high 



Stem stout, glabrous or harshly pubescent ; leaves lanceo- 

 late to narrowly rhombic-obovate ; involucre 7-12 mm. 



high 



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



clasping P. 

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



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



smooth . 16. A. sericeus. 



Heads in a wand-like raceme ; achenes silky . . . . 17. A. concolor. 

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

 Q. Involucre glandular-viscid ; rays violet R. 

 R. Basal leaves petioled, much larger than the cauline. 



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

 oles ; involucral bracts erect 7. A. Herveyi. 



Basal leaves narrower, on margined petioles ; involucre 



squarrose. 

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



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



Low ; basal leaves lanceolate ; involucre mostly shorter, 



barely glandular 9. A. swculosus. 



R. 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 into involucral 



bracts 12. A. grandiflorus. 



Stem glandular-puberulent ; uppermost leaves and invo- 

 lucral bracts distinct . 13. A. oblongifolius. 



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

 Q. Involucre not glandular 8. 

 S. Basal leaves with definite margined petioles. 

 Involucral bracts oblong, coriaceous. 

 Leaves entire or slightly dentate. 

 Bracts strongly ciliate ; involucre turbinate-hemispher- 



ical 9. A. surculosus. 



Bracts not ciliate, nearly or quite glabrous ; involucre 



slender-turbinate 10. A. gracilis. 



Leaves serrate 11. A. radula. 



Involucral bracts linear or linear-subulate, thin . . .47. A. tardiflorus. 

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

 spicuously so T. 

 T. Stem-leaves linear 17. 

 U. Stem glabrous or glabrate, or only slightly pubescent 



above V. 



V. Involucre 5 mm. or less high W. 

 W. Bracts with definite firm subulate tips. 



Involucre hemispherical or campanulate, as broad 



as high 38. A. ericoides. 



Involucre turbinate, only 2-3 mm. broad . . 34. A. depauperating 

 W. Bracts without firm subulate tips X. 

 X. Bracts with conspicuous elliptic or subrhombic 



green tips. 



Heads terminating minutely foliose branchlets . 38. A, dumosus. 

 Heads paniculate or if few on leafy (not minutely 



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

 X. Bracts attenuate, without conspicuous dilated tips. 

 Rays white (or lavender-tinged). 

 Branches ascending-paniculate ; heads in ra- 

 cemo-paniculate clusters. 



GRAY'S MANUAL 51 



