Gen. N. Amer. Pl. 2: 179. 1818.
Perennials, 10–30 (–60) cm. Internodes (± mid-stem) 1–4 (–5+) cm. Leaves mostly cauline; opposite; petioles 0–1 mm, ciliate or not; blades lance-linear to linear or filiform, 20–45 (–60) × 1–2 (–3+) mm, rarely with 1–2 lateral lobes. Peduncles 2–4 (–6+) cm. Calyculi of oblong to linear bractlets 1.5–2+ mm. Phyllaries deltate-ovate, 4.5–5.5 mm. Ray laminae pinkish to white, 9–15+ mm. Disc-florets 40–60+; corollas ochroleucous to yellow, 2.5–3 mm. Cypselae narrowly oblong, 1.3–1.8 mm, not winged; pappi 0.2n = 26.
Phenology: Flowering Aug–Sep.
Habitat: Sandy shores, marsh edges, etc.
Elevation: 0–50 m
N.S., Del., Mass., N.J., Pa., R.I., S.C.
Occurrence of Coreopsis rosea in South Carolina may represent a human-mediated disjunction; the collection came from a “lime sink” near a trailer park close to a freeway.
"broader" is not a number.