GENUS 35. 



THISTLE FAMILY. 



3. Erigeron subtrinervis Rydberg. Three- 

 nerved Fleabane. Fig. 4363. 



Erigeron glabellus var. mollis A. Gray, Proc. Acad. 

 Phila. 1863: 64. 1864. Not E. mollis D. Don. 



Erigeron subtrinervis Rydberg, Mem. Torr. Club 5 : 

 328. 1894. 



Similar to the preceding species, perennial by 

 a woody root, finely pubescent all over; stems 

 leafy to the inflorescence. Leaves entire, thin, the 

 basal and lower ones oblanceolate to oblong, ob- 

 tuse or acute, petioled, the upper lanceolate or 

 ovate-lanceolate, sessile or somewhat clasping, 

 acute, rather distinctly 3-nerved; heads i'-ii' 

 broad, corymbose, or rarely solitary; involucre 

 hemispheric, hirsute; rays numerous, blue to pink; 

 pappus double, the outer bristles very short. 



In dry soil, South Dakota to Wyoming, Nebraska, 

 Utah and New Mexico. July-Sept. 



4. Erigeron caespitosus Nutt. Tufted 

 Erigeron. Fig. 4364. 



Diplopappus canescens Hook. Fl. Bor. Am. 2: 21. 



1834. Not E. canescens Willd. 1804. 

 Erigeron caespitosus Nutt. Trans. Am. Phil. Soc. (II) 



7:307. 1841. 



Perennial by a deep root; stems tufted, canes- 

 cent, simple, or branched above, 6'-i2' high. 

 Leaves canescent or pubescent, entire, the lower 

 and basal ones petioled, narrowly oblanceolate 

 or spatulate, obtuse or acutish, i'~3' long; stem 

 leaves linear or linear-oblong, acute or obtuse, 

 sessile, the upper gradually shorter, heads soli- 

 tary or several, short-peduncled, i'-ii' broad; in- 

 volucre hemispheric, its bracts lanceolate or linear- 

 oblong, acute, canescent; rays 40-60, 3"-6" long, 

 white or pinkish ; pappus double, the outer series 

 of bristles very short. 



In dry soil, Manitoba to Yukon, Nebraska (accord- 

 ing to Webber), British Columbia and Colorado. 

 June-Aug. 



5. Erigeron pumilus Nutt. Low Erigeron. 

 Daisy. Fig. 4365. 



Erigeron pumilis Nutt. Gen. 2: 147. 1818. 



Perennial by a deep root; stems tufted, hirsute, slen- 

 der, simple, or branched, 4'-io' high. Leaves entire, 

 hirsute, the lower and basal ones narrowly spatulate or 

 linear, petioled, obtuse or acutish, i'~4' long, i"-2" wide ; 

 stem leaves linear, sessile, \'-2\' long, acute; heads soli- 

 tary or several, 6"-io" broad, short-peduncled ; invo- 

 lucre hemispheric, its bracts linear, acute, hirsute; rays 

 50-80, white, 3"-4" long, at length deflexed ; pappus 

 double, the outer row of bristles short and more or less 

 intermixed with the inner; achenes pubescent. 



Dry plains, North Dakota to western Nebraska, Kansas, 

 British Columbia, Colorado and Utah. May-Sept. 



