66. Erigeron purpuratus Greene, Pittonia. 4: 155. 1900.
Perennials, (2–)3–9(–14) cm; taprooted, caudices diffuse with extensive systems of rhizomelike, relatively long and slender branches. Stems erect (simple, ± scapiform), villous, minutely glandular. Leaves mostly basal (persistent); blades linear to narrowly oblanceolate, 15–30(–45) × 1–2.5(–3) mm, margins entire or (mostly on early leaves) with 1–2 shallow lateral lobes or teeth, faces sparsely hirsuto-villous or glabrous, minutely glandular. Heads 1. Involucres 6–9(–10) × 9–15 mm. Phyllaries in 2–3 series, sparsely pilose (hairs 1–3 mm, with colored cross walls) or glabrous, minutely glandular. Ray florets 40–90; corollas white to pink or purplish, 5–9 mm, laminae (filiform, 0.3–0.8 mm wide, involute) erect, not coiling or reflexing. Disc corollas 4–5 mm. Cypselae 1.8–2.7 mm, 2-nerved, faces sparsely strigillose to glabrate; pappi: outer 0 (or inconspicous), inner of 28–40 (pinkish to purplish) bristles. 2n = 18.
Flowering Jun–Aug. Sandy and gravelly stream banks, gravel bars, sandy beaches, gravelly slopes, alpine tundra; 100–1400 m; Yukon; Alaska.
The erect, involute ray laminae of Erigeron purpuratus, E. denalii , and E. pallens distinguish them from other species of sect. Tridactylia. Distinctions among these species were studied by G. L. Nesom and D. F. Murray (2004).