19. Coreopsis lanceolata Linnaeus, Sp. Pl. 2: 908. 1753.
Perennials, 10–30(–60+) cm. Aerial nodes proximal to first peduncle usually 1–3(–5+), distalmost 1–3 internodes 1–2(–8+) cm. Leaves: basal and cauline on proximal 1/4–1/3(–1/2) of plant heights; petioles 1–5(–8+) cm; blades simple or with 1–2+ lateral lobes, simple blades or terminal lobes lance-ovate or lanceolate to oblanceolate or lance-linear, 5–12 cm × 8–15(–18+) mm. Peduncles (8–)12–20(–35+) cm. Calyculi of lance-ovate to lance-linear or linear bractlets 4–8(–12) mm. Phyllaries deltate to lance-deltate, 8–12+ mm. Ray laminae yellow, 15–30+ mm. Disc corollas 6–7.5 mm, apices yellow. Cypselae (2.6–)3–4 mm, wings ± spreading, ± chartaceous, entire. 2n = 26 (+ 0–4B).
Flowering (Mar–)May–Jul(–Aug). Sandy soils, ditches and roadsides, other disturbed sites; 30–500(–1000+) m; B.C., Ont.; Ala., Ark., Fla., Ga., Ill., Ind., Kans., Ky., La., Md., Mich., Miss., Mo., N.J., N.Mex., N.Y., N.C., Ohio, Okla., Pa., S.C., Tenn., Tex., Vt., Va., W.Va., Wis.
Plants that have been called Coreopsis lanceolata var. villosa Michaux often have 5+ aerial internodes 6+ cm long proximal to the first peduncle; they may merit recognition as a distinct taxon or may be hybrids (or derivatives) from crosses between C. lanceolata and C. pubescens.