Cleftleaf groundsel

Senecio subnudus de Candolle in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 6: 428. 1838, not de Candolle [Prodr. 6: 405] 1838; Packera buekii Trock & T. M. Barkley; Senecio aureus Linnaeus var. subnudus (de Candolle) A. Gray; S. cymbalarioides Buek

Perennials, 10–30+ cm; fibrous-rooted and/or rhizomatous (bases relatively slender, horizontal to suberect). Stems usually 1, rarely 2–3, loosely clustered, glabrous. Basal leaves petiolate; blades ovate, obovate, or elliptic, 20–40+ × 10–30+ mm, bases tapering to contracted, margins subentire to crenate-dentate. Cauline leaves abruptly reduced (sessile, often weakly clasping, dentate to subentire; distals sessile, lanceolate, weakly clasping, entire or dentate). Heads 1(–5; sometimes subtended by 2 relatively large bractlets). Peduncles sparsely bracteate or ebracteate, glabrous. Calyculi (bractlets frequently cyanic). Phyllaries (13–)21, green (tips sometimes cyanic), 5–8+ mm, glabrous. Ray florets 13; corolla laminae 7–12+ mm. Disc florets 40–55+; corolla tubes 2.5–3.5 mm, limbs 2.5–3.5 mm. Cypselae 1.5–2.5 mm, glabrous; pappi 4–6 mm. 2n = 46, 90.

Varieties 2 (2 in the flora): nw North America.