Wilken’s fleabane

Perennials, 10–20 cm (occurring mostly singly); taprooted, caudices simple or branches relatively slender. Stems erect, sparsely strigillose (hairs white, stiff), eglandular. Leaves mostly basal (persistent); (gray-green) blades narrowly oblanceolate to subspatulate, 9–62 × 1–5 mm, cauline linear-bractlike (bases enlarged, purplish-membranous), margins entire, faces sparsely and closely strigose, eglandular. Heads 1. Involucres 3.4–4.6 × 6–8.5 mm. Phyllaries in 2–3 series, sparsely hirsute, minutely glandular. Ray florets (8–)11–12; corollas adaxially white, abaxially light pink, 4.5–6 mm, laminae not coiling or reflexing. Disc corollas 2.2–3.5 mm. Cypselae ca. 1.8 mm, 2-nerved, faces sparsely strigose; pappi: outer apparently 0, inner of (12–)20–30 bristles.

Flowering May–Jun. Sloping alluvium and colluvium at w-facing bases of sheer sandstone walls; of conservation concern; 1500–2300 m; Colo.

Erigeron wilkenii is known only from Pool Canyon in Dinosaur National Monument.