512 



COMPOSITAE (composite FAMILY) 



Heads few to several, corymbed. 



Heads small; leaves linear, or the lower spatulate 



to lanceolate . . 

 Heads large; leaves ample, ovate or oblong, 8—12 

 cm. long ........ 



Heads in a narrow crowded panicle; leaves large, ob- 

 lanceolate to lanceolate ..... 



Stems branched. 



More or less scabrous-hispid or -ciliate. 



Tall and coarse, 6-15 dm, high ..... 



Low and ri^id, 1-4 dm. high. 



Leaves hispidulous-scabrous,' spreading or deflexed . 

 Leaves ciliaterhispid on the margins, ascending 

 Leaves glabrate, granular-glandular .... 



Peduncles and involucres not glandular. 



Leaves not glabrous on their faces, cinereous, scabrous, or 

 hirsutulous. ■ ' 

 Stems subsimple, erect, with a few erect or ascending 

 branches oearing soli€kry or few rather large heads 

 (1 cm. high) 

 Leaves cinereous; rays violet 

 Leaves obscurely scabrous; rays white 

 Stems divaricately branched; heads many to very nu- 

 merous, small (less than 1 cm. high). 

 Bracts unequal, usually hispidulous; heads small, very 

 numerous. 



All the bracts acute 



Some of the bracts obtuse . . , - , 

 Bracts subequal; heads larger and fewer. 

 Heads paniculate . . . . 

 Heads strictly axillary-racemose .... 

 Leaves glabrous on their faces (pubescence, if any, not 

 harsh), often ciliate or hispid on the margins. 

 Outer involucral bracts shorter than the inner (not folia- 

 ceous). 

 Stems and peduncles wholly glabrous. _ 

 Leaves linear, none auriculate-clasplng. 



Leaves l-nerved; heads paniculate . . , 



Leaves 3-nerved; heads in a flat-topped corymb . 



Leaves broadly oblanceolate, oblong, or lanceolate, 



the upper auriculate-clasping. 



Leaves abruptly reduced in size on the branches . 



Leaves gradually reduced in size on the branches 



Stems and peduncles pubescent at least in longitudinal 



lines. 



Lower leaves ovate-cordate, often serrate, loog- 



petioled 



Lower leaves oblanceolate, lanceolate, or linear. 

 Pubescence of branchlets characteristically in lines. 

 All the bracts narrowly linear .... 



Outer bracts broader than the inner 

 Pubescence of branchlets m^ore or less uniform, not 

 characteristically in lines. , 



Bracts ascending or erect, not refractea. 



Bracts oblanceolate, usually some of the outer 

 obtuse. 

 Stems slender, erect, 4r-7 dm. high 

 Stems stouter, ascending, 2-4 dm. high 

 Bracts broadly oblong to linear-lanceolate or 

 linear, all acute. 

 Stem leaves oblanceolate to linear. 

 Heads several to many, paniculate 

 Heads few (rarely solitary), in a flat- 

 topped corymb .... 



Stem leav^ ovate, elliptic, or ovate- 

 lanceolate. 

 Stems simple below .... 



Stems branched from the base 

 Bracts refracted (at least some of them) . " . 

 Outer involucral bracts as long as or longer than the inner, 

 more or less foliaceous. 

 Bracts refracted (at least some' of them) . . . 34. A. proximua. 

 K*acts ascending or erect. 

 Plants low (1-3 dm.). 



Outer bracts little, if any, longer than the inner . 35. A. apricus. 

 Outer bracts foliaceous, much longer than the 



inner . . ..... 36. A fulcratus. 



Plants tall (4-8 dm.). 



Bracts mostly linear 37. A. frondeua. 



Bracts oblong or oblanceolate .... 32. A. Canb^i. 



9. A. pauciflorua. 



10. A. conspicuus. 



11. A. integrifolius. 



12. A. novae-angliae 



13. A. oblongifolius. 



14. A. Fendleri. 



15. A. . campestris. 



16. A. griseus. 



17. A. ptarmicoides. 



18. A. multiflorus. 



19. A. hebecladus. 



20. A. comm.utatus, 



21. A. Cordineri. 



22. A. Porteri. 

 17. A. ptarmicoides. 



23. A. laevis. 



24. A. Geyeri, 



25. A. Lindleyanus. 



26. A. caerulescens. 



27. A. laetevirens. 



28. A. Nelaonii. 



29, A. adscendens. 



30. A. longifolius. 



31. A. Fremontii. 



32. A. Canbyi. 



33. A. meritus. 

 S4. A. proximua. 



