524 COMPOSITAE (COMPOSITE FAMILY) 



Bracts appressed-hirsute ..... 20. E. Eatonii. 



Herbage conspicuously hispid or hirsute-ciliate . . 24. E. pumilus. 



Leaves 3-nerved, at least at base. .... 23. E. microlonchus. 

 Rays not white. 



Pubescence very short. 



Leaves 3-nerved ....... 25. E. corymbosus. 



Leaves 1 -nerved 26. E. caespitosus. 



Pubescence hispid, long and spreading . . . 27. E. concinnus. 



Leaves dissected or deeply cleft. 

 Leaves ternately divided. 



Twice to thrice ternate ....... 28. E. compositus. 



Once ternate or quinate 29. E. trifidus. 



Leaves pinnately divided ....... 30. E. pinnatisectus. 



ANNUALS OR BIENNIALS 



Leaves not cordate-clasping. 



Stems simple at least below; the heads few, large. 



Involucre hirsute or strigose . . . . . 8. E. asper. 



Involucre more or less glandular or viscid . . . 9. E. formosissimus. 



Stems branched; the heads small, several to many. 



Stems simple at base but branching upward . . . 31. E. ramosus. 

 Stems branching from the base and in no. 32 also above. 



Leafy throughout . . . . . . .'*.. 32. E. divergens. 



Leafy below and terminating in a scape-like peduncle. 

 The few stems erect, but sometimes with a few short 



stolons from the base ...... 33. E. colo-mexicanus. 



The earlier stems erect, the later slender-stoloniferous, 



leafy and often rooting ..... 34. E. flagellaris. 



Leaves cordate-clasping 35. E. philadelphicus. 



RAYS INCONSPICUOUS (short or wanting) 

 Inflorescence corymbiform or paniculate. 



Plant 3-6 dm. high; stem mostly solitary ..... 36. E. lapiluteus. 



Plant 1-3 dm. high; stems often several ..... 37. E. acris. 

 Inflorescence mostly racemose; the stem or stems slender . . 38. E. lonchophyllus. 



1. Erigeron salsuginpsus Gray, Proc. Am. Acad. 16: 93. 1880. Root- 

 stocks short and thickish; stems 2-5 dm. high, the summit of peduncles 

 lanate-pubescent or puberulent, no bristly or hirsute hairs : leaves very smooth 

 and glabrous or glabrate, thickish; radical and lower cauline leaves spatulate 

 to nearly ob ovate, with base attenuate into a margined petiole, 3-7 cm. long; 

 upper cauline ovate-oblong to lanceolate, sessile, mucronate or apiculate- 

 acuminate; uppermost small and bract-like: bracts of the involucre loose or 

 even spreading, linear-subulate or attenuate, viscid ulous or puberulous: disk 

 12-14 mm. in diameter: rays broad, giving an Aster-like effect, 50-70, purple 

 or violet, 12-15 mm. long. On wet ground; in the mountains of our range 

 and far northwestward. 



la. Erigeron salsuginosus glacialis Gray, Syn. Fl. 1: 209. 1886. Lower, 

 few-leaved, often monocephalous. This and var. angustifolius grade into the 

 species, (E. glacialis A. Nels. Bot. Gaz. 37: 207. 1904.) Alpine stations. 



2. Erigeron elatior (Gray) Greene, Pitt. 3: 163. 1897. Stems somewhat 

 clustered, stout, erect, 4-7 dm. high, leafy up to the monocephalous or usually 

 distinctly corymbose summit, hirsute-pubescent, the foliage scabrous: leaves 

 ovate-lanceolate, acute, entire: heads 1-8, on bracted peduncles; involucres 

 very large, often more than 12 mm. high and 15-18 mm. broad; the linear, 

 attenuate-acuminate bracts squarrose-spreading, imbedded in dense, soft 

 wool: rays showy, numerous and narrow: achenes pubescent; pappus of rather 

 firm bristles and a conspicuous outer circle of white squamellae. E. grandi- 

 florus elatior. Along streams; in the mountains of our range. 



3. Erigeron Coulter! Porter, Fl. Col. 61. 1874. Stems 2-5 dm. high, equably 

 leafy, bearing solitary or rarely 2 or 3 slender-pedunculate heads: leaves 

 membranaceous, obovate to oblong, either entire or serrate with several sharp 

 teeth, pilose-pubescent to glabrous; the cauline hardly mucronate: disk about 

 12-14 dm. wide: involucral bracts less attenuate and spreading, obscurely vis- 

 cidulous but hirsute with spreading hairs: rays rather narrowly linear, 12 mm. 

 or more long, white, varying to purplish. In the mountains of our range. 



4. Erigeron superbus Greene, ex Rydb. Fl. Col. 364. 1906. Nearly 

 glabrous throughout, 3-6 dm. high, nearly simple and strict: leaves rela- 

 tively few and distant, rather large, sparsely ciliate; the basal and lower 



