Coreopsis lanceolata L.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Clustered perennial 2–6 dm from a short caudex, glabrous or spreading-villous; stems leafy below, elongate and naked above; lvs spatulate to linear or lance-linear, simple or with 1 or 2 pairs of small lateral lobes, the lower long-petiolate, mostly 5–20 cm overall and 0.5–2 cm wide; the others reduced and sessile or nearly so; heads few or solitary on long, naked peduncles, the disk yellow, 1–2 cm wide; outer bracts 8–10, lanceolate to oblong-ovate, ± scarious-margined, 5–10 mm; inner bracts longer and broader; rays 1.5–3 cm; receptacular bracts flat and chaffy below, caudate-attenuate above; disk-fls 5-toothed; style appendages cuspidately acute; achenes 2–3(–4) mm, orbicular or broader, with thin, flat wings; pappus of 2 short, chaffy teeth; 2n=24, 26, 48. Dry, often sandy places; Mich. and the n. shore of Lake Superior to Fla. and N.M.; cult. and often escaped. Apr.–June. (C. crassifolia; C. heterogyna)