Annual or short-lived perennial herb 90–150 cm tall, erect; stems pale green with reddish tinge, sparsely shortly pubescent.. Leaves sessile, elliptic, 3–21 cm long, 0.5–4 cm wide, attenuate to an exauriculate petioloid base or (especially the upper) sessile, margins shallowly and remotely to (especially the upper) coarsely sinuate-serrate, unlobed or (especially the upper) lyrato-pinnately or pinnately 2–8-lobed, apex ± attenuate and obtuse to acute, shortly pubescent.. Capitula discoid, several to numerous in lax terminal cymes, erect; stalks of the individual capitula glabrous or pubescent; involucre cylindrical, 6.5–7 mm long, 2.5–3 mm in diameter; bracts of calyculus 9–12, lanceolate, dark-tipped, 1.5–3.5 mm long, ciliate; phyllaries 13, pale green with dark tips, 6–6.5 mm long, sparsely shortly pubescent.. Disc florets mauve or pinkish-mauve (label of type says white), corolla 8–9 mm long, tube glabrous, gradually expanded above the middle, lobes 1–1.2 mm long.. Achenes 1.8–2 mm long, ribbed, hairy between the ribs; pappus 6–8.5 mm long.