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 rigid, 1-4 dm. high. 



Leaves hispidulous-scabrous, spreading or deflexed . 

 Leaves ciliate-hispid 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 bearing solitary 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-clasping. 

 Leaves 1-nerved; heads paniculate 

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

 Leaves broadly oblanceolate, 9blong, 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, long- 

 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 more or less uniform, not 



characteristically in lines. 

 Bracts ascending or erect, not refracted. 



Bracts oblanceolate, usually some of the outer 



obtuse. 



Stems slender, erect, 4-7 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 leaves 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) 

 Bracts ascending or erect. 

 Plants low (1-3 dm.). 



Outer bracts little, if any, longer than the inner . 

 Outer bracts foliaceous, much longer than the 



inner 

 Plants tall (4-8 dm.). 



Mrncts mostly linear ...... 



Bracts oblong or oblanceolate 



9. A. pauciflorus. 



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. commutatus. 



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. Nelsonii. 



29. A. adscendens. 



30. A. longifolius. 



31. A. Fremontii. 



32. A* Canbyi. 



33. A. meritus. 



34. A. proximus. 



34. A. proximus. 



35. A. apricus. 



36. A fulcratus. 



37. A. frondeus. 

 32. A. Canbyi. 



