Annual herb, erect, 1–2 m high; stem solitary, branching in the distal part of the plant, glabrous. Leaves cauline, sessile, oblanceolate to broadly elliptic, pinnatilobed with spreading lobes, 6–20 cm long, 2–10 cm wide, base subauriculate, lobes deltoid, to 4 cm long, margins dentate, apex obtuse and apiculate, glabrous. Capitula many, subsessile in large, lax panicles with long side branches; stalks of individual capitula 1–10 mm, sometimes pilose; involucre 10–12 mm long, conical-cylindric to spreading; phyllaries green, tinged with brown, ovate (outer) to lanceolate (inner), 1.5–12 mm, the outer extending down the stalk, acute, margins not or hardly hyaline, glabrous or minutely ciliate at the very apex. Corolla yellow, tube 4–5.5 mm long, distally pilose, ligule 5 mm long. Achenes grey, fusiform, 2.5–3 mm long, with 4 main ribs and 8 thinner ones, all muricate, the apex slightly narrowed; pappus white, 7–8 mm long, of mixed setae and downy hairs.