Proc. Amer. Acad. Arts 51: 525. 1916.
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 lanceovate, 7–9+ mm. Ray laminae yellow, usually each with a proximal, redbrown to purple spot or band, 15–20+ mm. Disc corollas 3–4 mm, apices redbrown to purple. Cypselae 1.2–1.8 mm, wingless (margins ± inrolled adaxially, ± corky). 2n = 26.
Phenology: Flowering Apr–Jun.
Habitat: Sandy soils in open, often disturbed, places
Elevation: 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.
"broader" is not a number.