Oldfield sneezeweed

Perennials, 40–100 cm. Stems usually 1, branched distally, moderately to strongly winged, densely (the proximal) to moderately hairy. Leaves moderately to densely hairy; basal blades oblanceolate to obovate to spatulate, entire or undulate-serrate; proximal and mid blades oblanceolate to lanceolate, usually entire, sometimes undulate-serrate; distal blades lanceolate to lance-linear, entire. Heads 3–20 per plant, in paniculiform to corymbiform arrays. Peduncles 3–11 cm, moderately to densely hairy. Involucres globoid to ovoid, 9–17 × 10–20 mm. Phyllaries (barely connate proximally) moderately to densely hairy. Ray florets 9–15, neuter; corollas yellow, 20–30 × 8–15 mm. Disc florets 150–500(–700+); corollas yellow proximally, reddish brown to purple distally, 3–5 mm, lobes 5. Cypselae 1–1.4 mm, sparsely to moderately hairy; pappi of 6–7, entire, non-aristate scales 0.3–0.5 mm. 2n = 28.

Flowering May–Jun(–Jul). Ditches, fields, in washes, along streams; 100–200 m; Ark.