Perennial herb arising from slender woody rhizomes; stems erect, to 3.5 dm tall; basal leaves obovate to oblanceolate 1.8-13.5 cm long, 6-27 mm wide, serrate with small shallow teeth, tapering at the base to a winged petiole; stem leaves similar, becoming gradually smaller and sessile above; flower heads 1-6 per stem on stalks 1-3 cm long; involucral bracts narrowly lanceolate, in three equal series, sparsely to densely pubescent; ray flowers 45-100 per head, white (occasionally drying lilac), 11-20 mm long; achenes oblong, laterally compressed but plump, sparsely appressed-hairy; pappus of 20-30 slender bristles. Flowers July to September.