Once in a while, a Calliopsis or Plains Coreopsis grows with solid red flowers. Naturally, this trait has been seized on by breeders to produce reliably red varieties, and this plant may well be a descendant of one of those domesticated breeds. It was growing in a hillside meadow in Scott Township, where it was blooming in late July.
Gray describes the genus and the species:
COREOPSIS L. TICKSEED. Heads many-flowered, radiate; rays mostly 8, neutral, rarely wanting. Involucre double; each series of about 8 bracts, the outer foliaceous and somewhat spreading; the inner broader and appressed, nearly membranaceous. Receptacle flat, with membranaceous chaff deciduous with the fruit. Achenes flat, obcompressed (i.e. flattened parallel with the bracts of the involucre), often winged, not narrowed at the top, 2-toothed or 2-awned, or sometimes naked at the summit; the awns not barbed downwardly. — Herbs, generally with opposite leaves and yellow or party-colored (rarely purple) rays. Too near the last section of Bidens, but generally well distinguished as a genus. (Name from koris, a bug, and opsis, appearance; from the form of the achene.)
§1. Style-tips truncate or nearly so; outer involucre small and short; rays rosecolor or yellow, with brown base; pappus an obscure border or none.
С. tinctoria Nutt. Annual, glabrous, often 1 m. high; leaves 1-2-pinnately divided, the lobes lanceolate to linear; achenes oblong, wingless; rays yellow, with more or less of crimson-brown. — Minn, to Tex., etc.; common in cultivation; often escaping to roadsides, etc., eastw.