1208 



CAKDUACEAE 



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

 cence broad-panicled. 18. A. cordifolius. 

 Bracts linear-acute or subulate. 

 Pubescence downy or absent. 



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



heads compound-racemed. 19. A. sagittifolius. 



Low : chief leaves falcate-lanceolate : sinus obsoles- 

 cent: heads thyrsoid. 20. A. plumarius. 

 Cinereous or canescent pubescence present. 



Plants toraentulose, very rough above : sinus broad. 

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



nish. 21. A. Inrtellus. 



Leaves prolonged, sharp-toothed, thick. 22. A. Drummondii. 



Plants but lightly pubescent. 



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

 row. 23. A. Tetanus. 

 Leaves long-triangular, thick : sinus little developed. 24. A. trigonicus. 

 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. 25. A. azureus. 



Chief leaves elliptic-lanceolate, crenate: pedicels con- 

 spicuous, nude. 26. A. capillactus. 

 Chief leaves grass-like : branches very diffusely decompound. 



Radical leaf-blades chiefly with truncate bases. 27. A. vernalis. 



Radical leaf-blades chiefly with taper bases. 28. A. poaceus. 



No dilated-clasping petioles. Biotian and Heterophyllous Asters, Nos. 1-28. 

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

 rowly toward the blade. Diversifolial Asters. 



Polymorphous leaf-forms present, no one type strongly predominant. 

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



divergently compound. 29. A. undulatns. 



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



racemose. 30. A. Proteus. 



Some predominant leaf-form present. 



Predominant leaves broad, not greatly elongated. 



Predominant leaves tomentulose beneath, ovate-oblong, thick and 



rough, diminutive. 31. A. asperifolius. 



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

 date, thinnish. 32. A. sylvestris. 

 Predominant leaves elongated. 



Predominant leaves triangular-attenuate. 



Slender plants : leaves chiefly petioled and clasping. 33. A. truellius. 



Robust when fully developed : leaves chiefly sessile. 



Leaf-bases narrow : axils usually foliose. 34. A. corrigiatus. 



Leaf- bases broad : leaves very rough. 35. A. triangular is. 



Predominant leaves not triangular. 



Predominant leaves linear-oblong with straight sides. 



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

 cence racemose. 36. A. linguiformis. 

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

 pound. 



Plant not glandular : leaves strap-shaped or thong-like. 37. A. loriformis. 



Plant somewhat glandular : leaves gra&s-like, narrower. 38. A. Mohrii. 



Predominant leaves ovate-oblong to elongated-lanceolate. 



Leaves firm, crisp : stem bearing stalked glands : inflorescence 



irregular, narrow, often clavate. 39. A. claviger. 



Leaves thinnish : plant without glands : inflorescence some- 

 what thyrsoid. 40 A. gracilescens. 



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



long- petioled , etc. Biotian, Heterophyllous and Diversifolial Asters, 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 Asters, Nos. 41-63. 



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

 Stem glabrous : leaves firm, sleek or subsucculent. 

 Involucre carnpanulate. 



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. 41. A. laevis. 



Cauline leaf- blades linear or elongated-lanceolate : inflores- 

 cence tending to the corymbose panicle. 42. A. concinnus. 

 Bracts linear, their green tips narrowly lanceolate. 



Cauline leaves linear or narrow-lanceolate. 43 A. purpuralus. 



Cauline leaves very narrowly linear': heads very small. 44. A. attenuatus. 



Leaves glabrous above, often with minute hair beneath. 



Leaves entire, short, oblong-elliptical, remote. 45. A. ursinus. 



Leaves often coarsely toothed, prolonged, linear in type. 46. A. falcidem. 



Involucre turbinate or clavate : leaf- blades scarcely clasping. 47. A. turbinellus. 



Stem and leaves pubescent with short hair : involucre campanulate or 

 turbinate. 



