Glab. herb up to 2 m. tall, with woody decumbent stems up to c. 2 cm. diam., branches ascending. Lvs on terete petioles up to 30 cm. or more long, winged and broadly auriculate at base; lamina 10-20 × 7·5-15·5 cm., membr., suborbicular, cordate and deeply lobed at base, acute at apex, margins sinuate, finely spinulose-serrate; upper lvs smaller, with large auricles, merging into narrow entire bracts of corymb. Capitula ∞ in large corymbs, 2-3·5 cm. diam.; phyll. linear-oblong, acute, pubescent to glab. Ray-florets 10-15; ligules bright yellow, narrow, spreading; disk-florets up to 35. Achenes narrow-oblong, ± pubescent. Pappus soft, cop., white.

2n = 60