3 86 



COMPOSITAE. 



[Vol. III. 



3. Erigeron subtrinervis Rydberg. 

 Three-nerved Fleabane. (Fig. 3813.) 



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



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



1802. 

 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, 

 obtuse or acute, petioled, the upper lanceolate 

 or ovate-lanceolate, sessile or somewhat clasp- 

 ing, acute, rather distinctly 3-nerved; heads 

 i'-i^' broad, corymbose, or rarely solitary; in- 

 volucre hemispheric, hirsute; rays numerous, 

 blue to pink; pappus double, the outer bristles 

 very short. 



South Dakota to Nebraska and Utah. 



4. Erigeron caespitosus Nutt. 

 Tufted Erigeron. (Fig. 3814.) 



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



1834. Not E. canescens Willd. 1804. 

 Erigeron caespitosus Nutt. Trans. Am. Phil. Soc. 



(11)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 / -i^ / broad; 

 involucre 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 and the Northwest Terri- 

 tory to Nebraska (according to Webber), New 

 Mexico and California. June-Aug. 



5. Erigeron pumilus Nutt. Low Erigeronv 

 (Fig. 3815.) 



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



Perennial by a deep root; stems tufted, hirsute, 

 slender, simple, or branched, 4 / -io / high. Leaves en- 

 tire, hirsute, the lower and basal ones narrowly spatu- 

 late or linear, petioled, obtuse or acutish, \'-\' long, 

 l // -2 // wide; stem leaves linear, sessile, Yz'-iYz' long, 

 acute; heads solitary or several, 6 // -io // broad, short- 

 peduncled; involucre hemispheric, its bracts linear, 

 acute, hirsute; rays 50-S0, 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, Northwest Territory to western Nebraska,, 

 west to British Columbia, Colorado and Utah. May-Sept 



