Brit. Fl. Gard. 2: plate 175. 1826.
Perennials, 40–60+ cm. Aerial nodes proximal to first peduncle usually 6–10+, distalmost 1–3 internodes 4–7+ cm. Leaves: mostly cauline on proximal 2/3–7/8 of plant heights; petioles 0 or 10–35+ mm; blades usually 1 (–2) -irregularly pinnately or ± pedately lobed with (3–) 5–9+ lobes, rarely simple, simple blades or terminal lobes narrowly lanceolate to linear or filiform, 15–45 (–90+) × (0.5–) 2–8 (–12+) mm. Peduncles 8–15 (–25+) cm. Calyculi of lanceolate to linear bractlets 3.5–9+ mm. Phyllaries lanceovate, 7–9 (–12) mm. Ray laminae yellow, 12–25+ mm. Disc corollas 3.3–4.8 mm, apices yellow. Cypselae 2–3+ mm, wings spreading, ± chartaceous, entire or irregularly toothed to pectinate. 2n = 26 (+ 0–2B).
Phenology: Flowering May–Aug.
Habitat: Sandy soils, ditches and roadsides, other disturbed sites, granite and sandstone outcrops
Elevation: 30–300+ m
Ont., Que., Ala., Ark., Conn., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mich., Miss., Mo., N.J., N.Mex., N.Y., N.C., Ohio, Okla., Pa., R.I., S.C., Tenn., Tex., Vt., Va., W.Va., Wis.
Coreopsis grandiflora var. inclinata J. R. Allison from glades in Alabama may merit recognition.
"broader" is not a number.