Aster exscapus Richardson in J. Franklin et al., Narr. Journey Polar Sea, 748. 1823; Townsendia sericea Hooker

Perennials, 1–3 cm (± pulvinate). Stems ± erect; internodes 0.1–1 mm, ± hirsute to strigose or glabrate. Leaves basal and cauline, blades ± spatulate to narrowly oblanceolate or linear, 12–40(–75) × 2–6+ mm, not fleshy, faces ± strigillose. Heads ± sessile (usually nestled among rosette leaves). Involucres ± hemispheric, (10–)12–25+ mm diam. Phyllaries 30–45(–60) in 4–6+ series, the longer narrowly lanceolate or linear to subulate, (10–)12–14(–17) mm (l/w = 6–9), apices obtuse to acute, abaxial faces sparsely strigillose or glabrate. Ray florets 11–40; corollas white adaxially, laminae (9–)12–18+ mm, glabrous abaxially. Disc florets 100–150+; corollas 6.5–9(–12+) mm. Cypselae 4(–6+) mm, faces hairy, hair tips glochidiform; pappi persistent; on ray cypselae 20–30 setiform scales 6–8+ mm; on disc cypselae 20–30+ setiform scales 6.5–11+ mm. 2n = 18.

Flowering Mar–Jun(–Aug). Openings in pine forests, meadows, gravelly hills, sandy soils; (1300–)1600–2300(–3300) m; Alta., Man., Sask.; Ariz., Colo., Idaho, Kans., Mont., Nebr., Nev., N.Mex., N.Dak., Okla., S.Dak., Tex., Utah, Wyo.; Mexico (Chihuahua).