Basal leaves oblanceolate to obovate, usually crenate. Involucres usually 2.6-4.2+ mm (larger in tetraploids). Disc corolla lobes 0.5-0.9(-1) mm. Cypselae usually only sparsely strigose; pappi usually not or barely exceeding ray corolla tubes and bases of disc corolla lobes. 2n = 18, 36. Flowering Aug-Oct(-Nov, s). Open sandy, gravelly, and clay soils, disturbed sites, roadsides, prairies, fields; 0-1000+ m; Man. , N.B., N.S., Ont., P.E.I., Que.; Ala., Ark., Conn., Del., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Nebr., N.H., N.J., N.Y., N.C., N.Dak., Ohio, Okla., Pa., R.I., S.C., S.Dak., Tenn., Tex., Vt., W.Va., Wis. Subspecies nemoralis is found in the open, disturbed soils of fields, roadsides, and gravelly embankments in the eastern deciduous forest area. Plants of the southeastern United States with a few elongated proximal branches in the arrays have been treated as var. haleana; that trait occurs farther north on occasion and not all shoots of the same plant have it. It is treated here as a synonym of the typical subspecies. Diploids occur throughout the range; tetraploids are scattered.