Stems usually erect, sometimes decumbent or procumbent (rooting at nodes). Leaf blades triangular to deltate or ovate, 2-7(-13) cm, bases usually cuneate to truncate, rarely subcordate, margins serrate to serrate-dentate or crenate, apices acute. Phyllaries 3.5-4 mm. Corollas blue to blue-violet or rosy-violet, (1.6-)2-2.5 mm. Cypselae 1-1.5 mm, glabrous; pappi: bristle tips not dilated. 2n = 20. Flowering (Jun-)Aug-Nov. Stream banks, lakeshores, coastal and inland sands, pine-oak woodlands, low woods, flood plains, ditches, ravines, bogs, wet slopes, pine savannas, disturbed sites, roadsides, along railroads; 50-400 m; Ont.; Ala., Ark., Del., Fla., Ga., Ill., Ind., Kans., Ky., La., Md., Mich., Miss., Mo., Nebr., N.J., N.Y., N.C., Ohio, Okla., Pa., S.C., Tenn., Tex., Va., W.Va.