Helenium microcephalum var. oöclinium
Sida 5: 47. 1972.
Plants 25–80 cm. Leaves: proximal and mid blades serrate to undulate-serrate to occasionally deeply toothed or laciniate, glabrate; distal blades glabrous or sparsely to moderately hairy. Heads 20–100+ per plant. Peduncles 1.5–8 cm, usually projecting terminal heads well beyond foliage. Involucres 8–12 × 8–12 mm. Ray florets 9–13; corollas usually yellow throughout, sometimes reddish proximally and yellow distally, 2.7–9.1 × 1.5–6.7 mm. Disc florets 200–400+; corollas 1.7–2.4 mm, lobes 5. Pappi 0.4–0.7 mm. 2n = 26.
Phenology: Flowering (Mar–)Apr–Jun(–Dec).
Habitat: Sandy or clay soils, ditches, washes, around ponds and lakes, along streams
Elevation: 500–1900 m
Tex., Mexico (Coahuila, Nuevo León, Durango, San Luis Potosí).