Erect or ascending, annual herb, 10-60 cm tall. Stems glabrous or sparsely to densely hairy, usually becoming glabrous or sparsely hairy below, much- branched above and below. Basal and lower cauline lvs sparsely to moderately hairy especially when young, usually becoming almost glabrous above, petiolate; petiole < lamina, amplexicaul and often toothed or auriculate at base; lamina lyrate-pinnatifid to 1-2-pinnatisect, ovate, oblong, or obovate, obtuse and often mucronate at apex, 4-10-(20) × 1-3-(6) cm; segments obovate irregularly dentate; venation pinnate. Upper cauline lvs becoming smaller, shortly petiolate or apetiolate and often amplexicaul, and with narrower segments. Capitula 1-many, in loose corymbs. Supplementary bracts 11-16-(24), ovate-triangular to oblong, 2-5 mm long. Involucral bracts 13-14, oblong, glabrous, 5-9 mm long. Ray florets 12-17-(numerous); ligules usually purple, or purplish pink, sometimes pale or rarely white, 7-17 mm long. Disc yellow. Achenes terete or slightly flattened, with hairs between ribs, 2.3-3 mm long; pappus 5-8 mm long.