Sketch Bot. S. Carolina 2: 441. 1823.
Perennials, 20–70(–90+) cm. Aerial nodes proximal to first peduncle usually (5–)6–12+, distalmost 1–3 internodes 4–6(–10+) cm. Leaves: mostly cauline on proximal 2/3–7/8 of plant heights; petioles 2–10(–25+) mm; blades usually simple, rarely with 1–2(–3+) lateral lobes, simple blades or terminal lobes lance-elliptic to oblanceolate or lanceolate, 15–60(–80) × 2–25(–35) mm. Peduncles (7–)12–15+ cm. Calyculi of lanceolate to lance-linear bractlets 3–7 mm. Phyllaries lance-ovate to lanceolate, 5–8+ mm. Ray laminae yellow, 12–15+ mm. Disc corollas 4.6–5.4 mm, apices yellow. Cypselae 2.5–3 mm, wings ± spreading, ± chartaceous, entire. 2n = 26 (+ 0–2B).
Phenology: Flowering (Apr–)Jun–Aug(–Sep).
Habitat: Sandy soils, granite outcrops, open pine-oak woods, ditches and roadsides, other disturbed sites
Elevation: 30–1000+ m
Ala., Ark., Conn., Fla., Ga., Ill., Kans., Ky., La., Mass., Miss., Mo., N.C., Okla., S.C., Tenn., Tex., Va., W.Va.
Bushy to wiry, nearly glabrous plants with leaf blades mostly simple, mostly oblanceolate, and 2–15+ mm wide and with relatively small heads, florets, and fruits from coastal Mississippi and included here in Coreopsis pubescens may merit recognition as C. debilis Sherff or C. pubescens var. debilis.