Helenium setigerum (de Candolle) Britton & Rusby

Leaves: basal and proximal spatulate to oblanceolate, bases narrowed; mid ovate to lanceolate, bases usually semiclasping; distal leaves similar, smaller. Peduncles (4–)8–20 cm, expanded distally, sparsely pilose proximally, moderately to densely pilose distally. Involucres hemispheric to globose, 9–17 × 12–20 mm. Phyllaries: outer usually 8, inner 9–13. Ray corollas 10–22 × 4.5–9.6(–11.6) mm. Disc corollas 5.1–7 mm. Cypselae 3–4.5 mm; pappus scales 2–3(–4.1) mm, apices usually rounded to acute or acuminate, rarely cuspidate, not aristate. 2n = 34(?), 36, 37 (18II + 1I), 38, 39 (19II + 1I), 39 (18II + 3I ?), 40.

Flowering (Jan–)Mar–May(–Sep). Roadsides, open fields; 10–900 m; Tex.; Mexico (Coahuila, Nuevo León, Tamaulipas).