Eaton’s aster

Aster foliaceus Lindley ex de Candolle var. eatonii A. Gray in A. Gray et al., Syn. Fl. N. Amer. 1(2): 194. 1884 (as eatoni); A. bracteolatus Nuttall; A. eatonii (A. Gray) Howell; Symphyotrichum bracteolatum (Nuttall) G. L. Nesom

Perennials 40–100 cm, cespitose; short-rhizomatous. Stems 1–10+, ascending to erect, glabrous or sparsely puberulent. Leaves thin, margins entire or sometimes serrate, apices acute; basal withering by flowering, petiolate, blades narrowly lanceolate, 60–200 × 10–20 mm, attenuate or cuneate, margins usually entire, sometimes serrate, apices acute, faces glabrous or sparsely puberulent; proximalmost cauline sometimes withering by flowering, sessile, blades narrowly lanceolate, 50–150 × 8–25 mm, bases cuneate, often auriculate, apices acute; distal sessile, blades linear to narrowly lanceolate, 20–120 × 3–20 mm, bases cuneate, often auriculate , apices acute. Heads in racemiform to narrow, paniculiform arrays, branches usually to 10 cm. Peduncles sparsely hairy , bracts linear to lanceolate. Involucres campanulate, 5–8 mm. Phyllaries in 3–5 series, often spreading, oblanceolate (outer) to linear (inner), subequal, outer indurate less than ¹ / 2 , bases outer variable, inner scarious, margins entire, scabrous to ciliolate, green zones oblanceolate to elliptic, apices acute to obtuse, often spreading, faces glabrous or sparsely puberulent. Ray florets 20–40; corollas white to pink, laminae 7–15 × 1–2 mm. Disc florets 35–60+; corollas yellow, 4.5–5 mm, lobes triangular, 0.5–0.75 mm. Cypselae brown, cylindric to obovoid, not compressed, 2.5–3.5 mm, 1–2-nerved, faces hairy; pappi white, 5–6 mm. 2n = 16, 32, 48, 64.

Flowering Jul–Aug. Moist to wet sunny places, wet thickets, along streams and ditches; 500–3100 m; Alta., B.C., Sask.; Ariz., Calif., Colo., Idaho, Mont., Nev., N.Mex., Oreg., Utah, Wash., Wyo.