Glabrous perennial. Stem usually single, erect, not branched or branching above, finely grooved, (20)-50-100 cm tall. Rosette and lower stem lvs petiolate, 7-20 × 3-10 cm, lyrate-pinnatifid with a large triangular or reniform ternatifid coarsely toothed terminal lobe and 1-3 pairs of small ovate-hastate coarsely toothed lateral lobes; hydathodes prominent at tips of teeth; lamina thin, bright green above, pale and glaucous beneath. Upper lvs similar, with petiole becoming broadly winged and amplexicaul-auriculate at base; uppermost lvs not divided, linear to oblong, amplexicaul. Infl. diffusely paniculate. Capitula numerous, narrowly cylindric. Outer involucral bracts 2-4, very short, ovate to lanceolate, 1/10-? length of inner bracts. Inner involucral bracts linear, strictly erect, often purplish, 5-7 mm long; margins scarious. Receptacle areoles with raised glabrous margins. Florets 11/2× length of involucre; corolla pale yellow. Achenes usually 5 or fewer, dark brown to black, 10-ribbed, fusiform, flattened, very finely scabrid, shortly beaked, 3-4.5 mm long. Pappus bristles in 2 ± unequal rows, fine, white.