Plants 80–100+ cm. Stems strongly ridged. Basal leaves: (petioles 12–18+ cm) blades (lateral veins appressed to midveins 2–4 cm, then spreading) broadly ovate to narrowly oblong-lanceolate, 15–37 cm, margins usually entire, rarely sinuate or serrulate-denticulate. Cauline leaves: proximal petiolate, blades ovate (12–18+ cm, bases cuneate), margins serrate (apices acuminate); distal sessile, smaller. Involucres 10–12.5+ mm. Phyllaries (chalky white) ± ovate, midvein wings highest at bases. Corollas white, rarely tinged with pink, 9–10.5 mm. Cypselae cylindric to narrowly clavate, 4.2–5 mm; pappi 6–7 mm. 2n = 50.
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