16. Coreopsis basalis (A. Dietrich) S. F. Blake, Proc. Amer. Acad. Arts. 51: 525. 1916.
Calliopsis basalis A. Dietrich, Allg. Gartenzeitung 3: 329. 1835; Coreopsis basalis var. wrightii (A. Gray) S. F. Blake; C. wrightii (A. Gray) H. M. Parker ex E. B. Smith
Annuals, 10–50+ cm. Aerial nodes proximal to first peduncle usually 5–10+, distalmost 1–3 internodes 4–7(–10) cm. Leaves: basal and cauline on proximal 3/4–7/8 of plant heights; petioles 8–35(–120) mm; blades simple or 1(–2)-pinnately lobed with 3–9+ lobes, simple blades or terminal lobes elliptic or lanceolate to oblanceolate or linear, 25–55+ × (1–)2–9(–20) mm. Peduncles 6–15+ cm. Calyculi of lance-deltate to linear bractlets 6–9(–12+) mm. Phyllaries lance-ovate, 7–9+ mm. Ray laminae yellow, usually each with a proximal, red-brown to purple spot or band, 15–20+ mm. Disc corollas 3–4 mm, apices red-brown to purple. Cypselae 1.2–1.8 mm, wingless (margins ± inrolled adaxially, ± corky). 2n = 26.
Flowering Apr–Jun. Sandy soils in open, often disturbed, places; 10–300+ m; Ala., Ark., Fla., Ga., La., Miss., N.C., Okla., S.C., Tex.
Plants in the western part of the distribution of Coreopsis basalis usually have narrower lobes of leaf blades and narrower outer phyllaries; such plants have been treated as C. wrightii or as C. basalis var. wrightii.