Sp. Pl. 1: 507. 1753.
Plants to 8 dm, hispid to setulose. Stems simple or usually branching. Leaves to 15 cm; distal often somewhat clustered. Inflorescences: peduncle sparsely to moderately spreading-hispid throughout. Flowers: petals white, pink, orange, or red, often with dark basal spot, to 3.5 cm; anthers bluish; stigmas 5-18, disc ± flat. Capsules sessile or substipitate, turbinate to subglobose, obscurely ribbed, to 2 cm, less than 2 times longer than broad.
Phenology: Flowering spring–summer.
Habitat: Fields, pastures, stream banks, railroads, roadsides, and other disturbed sites
Elevation: 0-2000 m
Introduced; Man., N.B., N.S., Ont., Que., Sask., Alaska, Calif., Conn., D.C., Idaho, Ill., Iowa, La., Maine, Md., Mass., Mich., Minn., Mo., Mont., N.H., N.J., N.Mex., N.Y., N.C., Ohio, Oreg., Pa., R.I., Tex., Utah, Vt., Va., Wash., W.Va., Europe, sw Asia, n Africa.
J. W. Kadereit (1990) suggested that Papaver rhoeas originated on the east coast of the Mediterranean, probably derived from one or more of the other species of the section that are native in that region, and only after (and because) "suitable habitats in sufficient extent were provided by man." Various forms with pale pink or white, unspotted, sometimes doubled petals are grown for ornament, notably the Shirley poppies. In North America, the species escapes from cultivation fairly readily and has been introduced also as a crop weed.