Perennials 10–60 cm, colonial; long-rhizomatous. Stems 1–5+, ascending to erect, glabrous or sparsely puberulent. Leaves thin, margins entire or sometimes serrate, apices acute to obtuse, faces usually glabrous, sometimes sparsely hairy; basal usually persistent, petiolate to subpetiolate, blades broadly elliptic to obovate, 30–200 × 8–25(–30) mm, bases attenuate, margins entire or sometimes serrate, apices acute to obtuse; proximal cauline sessile or subpetiolate, blades elliptic to obovate, 35–120 × 8–25 mm, bases attenuate or cuneate to rounded, sometimes ± clasping, apices acute; distal sessile, reduced distally, bases cuneate, apices acute. Heads borne singly or in paniculiform arrays, branches ascending, up to 25 cm. Peduncles sparsely hairy, bracts 0–3, lanceolate. Involucres campanulate, 6–16(–20) mm. Phyllaries in 4–6 series, oblanceolate or oblong (outer) to lanceolate or linear (inner), subequal or unequal (outer exceeding inner), bases outer foliaceous, inner indurate, margins entire, green zones elliptic to lanceolate, apices acute to rounded, faces glabrous or puberulent. Ray florets 15–60; corollas violet to purple, laminae 8–18(–20) × 1–2 mm. Disc florets 50–150; corollas yellow, 4–7 mm, lobes triangular, 0.4–1 mm. Cypselae brown, cylindric to obovoid, not compressed, 2.5–4 mm, 3–4-nerved, faces hairy; pappi white to tawny, 5–8 mm.
Alta., B.C., Alaska, Ariz., Calif., Colo., Idaho, Mont., N.Mex., Nev., Oreg., Utah, Wash., Wyo.
Varieties 4 (4 in the flora).
Symphyotrichum foliaceum is extremely variable and is widespread in western montane coniferous forests and subalpine meadows.
|1||Plants 5–30 cm; heads 1–12; phyllaries subequal, narrowly lanceolate||> 2|
|1||Plants usually 20–60 cm; heads usually 5–20; outer phyllaries exceeding inner, wider, often foliaceous||> 3|
|2||Plants 5–20 cm; heads usually borne singly; phyllaries often purple-tinged; alpine or sub- alpine habitats||Symphyotrichum foliaceum var. apricum|
|2||Plants 10–30 cm; heads usually 1–12; phyllaries green; montane to subalpine habitats.||Symphyotrichum foliaceum var. parryi|
|3||Phyllaries obtuse to rounded; cauline leaves often clasping at base||Symphyotrichum foliaceum var. canbyi|
|3||Phyllaries acute; cauline leaves sometimes rounded at base, not clasping||Symphyotrichum foliaceum var. foliaceum|