Annuals or biennials (perennials with mild winters), 4-70 cm. Stems loosely strigose to sparsely hirsute, hirsuto-villous, or villous. Leaves: basal commonly withering by flowering, cauline faces sparsely hirsute to villous. 2n = 18. Flowering (Feb-)Mar-Jun(-Aug, in ne United States, Canada, and high elevations). Openings and margins of woods, marsh edges, creek sides, fields, roadsides, ditch banks, lawns, and other open, disturbed sites; 20-2900 m; Alta., B.C., Man., N.B., Nfld. and Labr. (Nfld.), N.W.T., N.S., Ont., P.E.I., Que., Sask., Yukon; Ala., Ark., Calif., Colo., Conn., Del., D.C., Fla., Ga., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Oreg., Pa., R.I., S.C., S.Dak., Tenn., Tex., Vt., Va., Wash., W.Va., Wis., Wyo.; introduced in Europe, Asia.