Sp. Pl. ed. 2, 2: 1493. 1763
Phenology: Flowering mid summer–fall.
Habitat: Disturbed sites, often in riparian habitats or in barnyards or on animal bed grounds, along roadsides and irrigation canals, with juniper, sagebrush, rabbitbrush, pinyon-juniper, Salsola, Chrysothamnus, Atriplex spp., and other weedy species
Elevation: 0-2600 m
Alta., B.C., N.S., Ont., Sask., Ariz., Calif., Colo., Fla., Idaho, Mass., Mich., Mo., Mont., Nebr., Nev., N.J., N.Mex., N.Y., N.Dak., Ohio, Oreg., Pa., Utah, Wash., Wis., Wyo., Eurasia.
At least some early collections were from ballast dumps at harbors on both coasts. It seems probable that the plants were quickly spread inland from initial centers of introduction by birds and more recently along railroads.