Biennials or perennials, 7-50(-70) cm; rhizomatous, caudices or rhizomes relatively short and thickened, simple or branched, usually appearing merely fibrous-rooted. Stems erect or slightly basally ascending, hirsute or hirsuto-villous to strigose or glabrate, eglandular. Leaves basal (persistent) and cauline; basal blades oblanceolate to oblanceolate-spatulate, 40-150 × 3-15 mm, margins usually entire, sometimes shallowly dentate, faces hirsute or hirsuto-villous to sparsely strigose or glabrate, eglandular; cauline blades usually becoming lanceolate, abruptly or gradually reduced distally (bases sometimes subclasping). Heads 1-15. Involucres 5-9 × 10-20 mm. Phyllaries in (2-)3-4 series (greenish) , hirsute to strigose, eglandular. Ray florets 125-175; corollas white to pink or blue, 8-15 mm, laminae (nearly filiform) coiling tardily at tips. Disc corollas 4-5.5 mm. Cypselae 1.2-1.5 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner of 16-20 bristles. Erigeron glabellus is recognized by its subsimple caudices and fibrous-rooted bases, relatively numerous rays with nearly filiform laminae, and nonglandular vestiture.
Hairy biennial or perennial 1-5 dm; lower lvs oblanceolate, to 15 cm נ15 mm or rarely more, the middle and upper ones evidently reduced, linear or lanceolate; heads solitary or several; disk 10-20 mm wide; invol 5-9 mm; rays 125-175, 8-15 mm, ca 1 mm wide, blue, pink or white; disk-cors 4.0-5.5 mm; pappus double; 2n=18, 36. Meadows, prairies, and open ground; Wis. to Alas. and Utah. Our plants, with spreading hairs, are the mostly northern var. pubescens Hook. (E. asper; E. abruptorum; E. drummondii; E. oligodontus; E. oxyodontus)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.