1208 



CARDUACEAE 



Leaves rough, thin : chief petioles not winged : inflores- 

 cence broad-panicled. 

 Bracts linear-acute or subulate. 

 Pubescence downy or absent. 



Tall: chief leaves ovate-lanceolate, thin : sinus open : 



heads compound-racemed. 

 Low : chief leaves falcate-lanceolate : sinus obsoles- 

 cent : heads thyrsoid. 

 Cinereous or canescent pubescence present. 



Plants tomentulose, very rough above : sinus broad. 

 Leaves cordate-ovate, crenate in. the middle, thin- 



nish. 

 Leaves prolonged, sharp-toothed, thick. 

 Plants but lightly pubescent. 



Leaves oval-acute, thinnish : sinus deep and nar- 

 row. 

 Leaves long-triangular, thick : sinus little developed. 

 B. Leaves rough on both sides, of a spongy, crumbling texture. 

 Chief leaves moderately broad : rays blue. 



Chief leaves oblong-lanceolate, shallow-serrate, short : 



pedicels bracteate. 

 Chief leaves elliptic-lanceolate, crenate : pedicels con- 

 spicuous, nude. 

 Chief leaves grass-like : branches very diffusely decompound. 

 Radical leaf-blades chiefly with truncate bases. 

 Radical leaf-blades chiefly with taper bases. 



Ko dilated-clasping petioles. Biotian and Heferophyllous Asters, Nos. 1-28. 

 Some petioles dilated, leaf-like and clasping around the stem, tapering nar- 

 rowly toward the blade. Diversifolial Asters. 

 Polymorphous leaf-forms present, ho one type strongly predominant. 

 Leaves not delicate, pubescent, rough when dry : inflorescence broad, 



divergently compound. 

 Leaves delicate, firm, rough, with little hair: inflorescence narrowly 

 racemose. 

 Some predominant leaf-form present. ' 



Predominant leaves broad, not greatly elongated. 



Predominant leaves tomentulose beneath, ovate-oblong, thick and 



rough, diminutive. 

 Predominant leaves sparse-pubescent beneath, petioled, short-cor- 

 date, thinnish. 

 Predominant leaves elongated. 



Predominant leaves triangular-attenuate. 



Slender plants : leaves chiefly petioled and clasping. 

 Robust when fully developed : leaves chiefly sessile. 

 Leaf-bases narrow : axils usually foliose." 

 Leaf-bases broad : leaves very rough. 

 Predominant leaves not triangular! 



Predominant leaves linear-oblong with straight sides. 



Leaves soft, thinnish : many long strap-like petioles : inflores- 

 cence racemose. 

 Leaves very rough, thick, usually sessile : inflorescence decom- 

 pound. 

 Plant not glandular : leaves strap-shaped or thong-like. 

 Plant somewhat glandular : leaves grass-like, narrower. 

 Predominant leaves ovate-oblong to elongated-lanceolate. 



Leaves firm, crisp : stem bearing stalked glands : inflorescence 



irregular, narrow, often clavate. 

 Leaves thinnish; plant without glands: inflorescence some- 

 what thyrsoid. 



18. A. cordifolius. 



19. A. sagittifolhis. 



20. ^4. plumarius. 



21. A. hirtellus. 



22. A. Drummondii. 



23. .1. Texanus. 



24. A. trigonicus. 



25. A. azureus. 



26. A. capillaceus. 



27. A. vervalis. 



28. A. puaceus. 



29. A. undulatvs. 



30. A. Proteus. 



31. A. aspirifolius. 



32. A. fylrestris. 



33. A. tnuUius. 



34. A. corrifiicitiis. 



35. A. triangularis. 



36. A. linguiforniis. 



37. A. loriformis. 



38. .4. Mo'hrii. 



39. .1. claviger. 



40. A. gracilescens. 



Basal and lower cauline leaves with relatively broad blades, ovate-cordate, 

 long- petioled, etc. Biotian, Heteropht/llmis and Diversifolial A.'iters, Nos. 1-40. 

 Basal and lower cauline leaves with relatively narrow blades, with more or less 

 contracted petiole-like bases but not cordate : upper cauline leaves with 

 sessile or clasping blades. 

 Blades of the cauline leaves more or less clasping by auriculate-cordate bases. 

 Amplexicaul A.'^ters, Nos. 41-63. 

 a. Chief bracts rigid, closely appressed (unless at the tip). 

 Stem glabrous : leaves firm, sleek or subsucculent. 

 Involucre campanulate. 



Leaves glabrous except the edges. 



Bracts oblong-linear with broad rhomboid or deltoid green tips. 

 Cauline leaf-blades oblong or oval-lanceolate : inflorescence 



tending to the racemose panicle. 

 Cauline leaf-blades linearor elongated-lanceolate : inflores- 

 cence tending to the corymbose panicle. 

 Bracts linear, their green tips narrowly lanceolate. 

 Cauline leaves linear or narrow-lanceolate. 

 Cauline leaves very narrowly linear : heads very small. 

 Leaves glabrous above, often witli minute hair beneath. 

 Leaves entire, short, oblong-elliptical, remote. 

 Leaves often coarsely toothed, prolonged, linear in type. 

 Involucre turbinate or clavate : leaf-blades scarcely clasping. 

 Stem ami leaves pubescent with short hair : involucre campanulate or 

 tiu'binate. 



41. A. laevis. 



42. A. concinnus. 



43. 



44. 



45, 



46. 

 47. 



A. purpuratus. 

 A. attenuatus. 



A. ursiiuis. 

 A. falcidi >i^. 

 A. turbiiieUus. 



