1. Erigeron Uniflorus L. Arctic Erigeron

Fig. 4361

Erigeron uniflorus L. Sp. Pl. 864. 1753- Perennial by short branching rootstocks; stems slender, single or .tufted, more or less pubescent, simple, erect, 1'-10' high. Basal leaves petioled, spatulate, obtuse, entire, 1-2' long; stem leaves sessile, lanceolate or linear-lanceolate, entire, acute or obtuse; head solitary, peduncled, 1/2'-l' broad; rays about 100, purple or purplish, 2"-4" long; involucre hemispheric, its bracts linear-lanceolate, acute, copiously woolly; pappus simple.

Labrador and Arctic America to Alaska, south in the Rocky Mountains to Colorado and in the Sierra Nevada to California. Also in Europe. Summer.

2. Erigeron Asper Nutt. Rough Erigeron

Fig. 4362

Erigeron asper Nutt. Gen. 2: 147. 1818. Erigeron glabellus Nutt. loc. cit. 1818.

Perennial by a woody root; stem simple, or branched above, more or less pubescent, sometimes hirsute, 6'-24' high. Leaves glabrous, pubescent or ciliate, entire, the basal ones spatulate, obtuse, 2-4' long, 3"-1' wide, narrowed into margined petioles; stem leaves oblong-lanceolate or linear-lanceolate, obtuse or acute, the upper smaller; heads several or solitary, slender-peduncled, 1-2' broad; involucre hemispheric, its bracts linear, acute, hirsute or pubescent; rays 100-150, very narrow, violet, purple, or nearly white, 4"-7" long; pappus double, the outer row of bristles much shorter than the inner.

In dry soil, Minnesota to Wisconsin, Nebraska, Manitoba, Utah and New Mexico. Races differ in pubescence. June-Sept.

3. Erigeron Subtrinervis Rydberg. Three-Nerved Fleabane

Fig. 4363

Erigeron glabellas 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, obtuse or acute, petioled, the upper lanceolate or ovate-lanceolate, sessile or somewhat clasping, acute, rather distinctly 3-nerved; heads 1'- 1 1/2' 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 Caespitdsus 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'-12' high. Leaves canescent or pubescent, entire, the lower and basal ones petioled, narrowly oblanceolate or spatulate, obtuse or acutish, 1-3' long; stem leaves linear or linear-oblong, acute or obtuse, sessile, the upper gradually shorter, heads solitary or several, short-peduncled, 1'-l 1/2' 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 to Yukon, Nebraska (according to Webber), British Columbia and Colorado. June-Aug.