Plants 50-250 cm (perennating bases ± erect, internodes winged). Leaves all or mostly alternate (proximal usually opposite); blades deltate-ovate or deltate to lanceolate, 4-10(-25+) × 2-6(-15) cm, bases broadly cuneate to ± trun-cate, margins coarsely toothed to subentire, apices obtuse to acute, faces ± hirtellous. Heads 30-80+ in ± paniculiform arrays. Involucres ± hemispheric, 5-7 mm diam. Phyllaries 12-15+ in 2 series, ± erect, spatulate to linear, 2.5-4 mm. Ray florets (9-)10-12+; laminae 4-6 mm. Disc florets 20-25+; corollas ochroleucous or white. Cypselae dark brown to blackish, oblanceolate, 4-5 mm, faces ± hirtellous or glabrous; pappi 1.5-2+ mm. 2n = 34. Flowering (May-)Jul-Sep(-Dec). Swales, disturbed sites; 10-100 m; Tex.; Mexico (Nuevo León, Tamaulipas).