Annuals, (10-)50-100(-150+) cm. Stems erect. Leaves: petioles 5-20(-30) mm; blades deltate or ovate to elliptic, trullate, or lanceolate, 30-100(-150+ × 8-45(-80) mm, margins ± toothed, faces ± scabrellous, gland-dotted. Heads in ± spiciform arrays. Peduncles 0-1 mm. Involucres ± hemispheric, 3-4(-5) mm. Phyllaries: outer 3-5 distinct, ± herbaceous. Paleae linear, 2-2.5 mm. Pistillate florets 3-5; corollas 0.5-1 mm. Functionally staminate florets 8-12+; corollas 2-2.5 mm. Cypselae 2-3 mm. 2n = 34. Flowering Jul-Nov. Disturbed sites, moist soils; 10-500 m; Ala., Ark., Colo., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Mass., Mich., Miss., Mo., Nebr., N.Mex., N.C., N.Dak., Ohio, Okla., Pa., S.C., S.Dak., Tenn., Tex., Va., W.Va., Wis.; Mexico (Tamaulipas).