Perennials, (15-)20-45(-60) cm (caudic­es erect or weakly spreading). Herbage nearly always glaucous, glabrous. Stems single or clustered. Leaves (thickish and turgid) progressively reduced distally; petiolate; blades ovate or obovate to lanceolate, 4-9(-15+) × 1.5-3(-4+) cm, bases tapered, margins wavy or subentire (often with callous denticles; mid and distal leaves sessile, bractlike). Heads (3-)8-24+ in corymbiform arrays. Calyculi of 1-3+ oblong to lance-linear bractlets (less than 3 mm). Phyllaries ± 13 (± 21), 6-9 mm, tips green to brownish (not blackened). Ray florets 8-10; corolla laminae 4-10 mm. Cypselae glabrous. 2n = 40. Flowering spring-summer. Damp or drying sites, often in rocky, moderately disturbed sites; 2000-3500 m; Ariz., Colo., N.Mex., Tex.; Mexico. Senecio wootonii reaches its southern limit in Coahuila and Chihuahua, Mexico; farther south, it is replaced by S. toluccanus de Candolle, a similar, larger, more robust species.