Yukon Groundsel

Perennials, 10–30(–40) cm (proximal stems and leaves floccose-tomentose, becoming glabrate, especially on the adaxial leaf faces; distal stems and phyllaries floccose-tomentose, hairs yellow; rhizomes creeping). Stems single or loosely clustered. Leaves basal and cauline (basal often withering before flowering); petioles unwinged or weakly so, 2–5 cm; blades ovate to broadly lanceolate, 2–5 × 1–3 cm, margins subentire to dentate or wavy (proximal cauline petioles usually winged, 0.5–1.5 cm, blades narrowly ovate to lanceolate, 2–4+ × 0.5–2 cm, margins subentire to wavy; mid and distal cauline smaller, clasping, bractlike). Heads 1–4(–6+). Involucres ± abruptly contracted to peduncles. Phyllaries mostly (13–)21, purplish (at least distally), 8–10(–12) mm. Ray florets (0) or 13–21; corolla laminae to 10 mm. Disc florets 40–60; corollas ochroleucous or white. Cypselae glabrous; pappi white. 2n = ca. 46 (48?).

Senecio yukonensis A. E. Porsild, Canad. Field-Naturalist 64: 44. 1950; S. alaskanus Hultén