Annual herb 0.2–1 m high, erect; stem simple or branched, reddish or speckled with reddish, glabrous or pilose. Leaves pinnate to bipinnatifid, 2–13 cm long and to 6 cm wide, segments 3–5, narrowly linear to filiform, to 50 by 2 mm, minutely ciliate and sometimes sparsely hispidulous; (pseudo)petiole to 50 mm long, narrowly winged. Capitula solitary and terminal; peduncle to 15 cm long; involucre 4–8 mm long, lengthening to 13 mm in fruit; outer phyllaries 4–9, green to reddish, often reflexing, glabrous or ciliate, inner phyllaries ± 8, pale brown with dark red or purple margins or red all over, glabrous or pubescent. Ray florets yellow, the upper part paler, neuter, 5–8, rays 6–7x1–1.5 mm, striate; disc florets yellow, campanulate, the lobes glabrous or puberulous. Achenes black or dark brown, narrowly ellipsoid with beak, appressed hairy; beak up to 2.5 cm or up to 24 cm long, with 2–3 aristae 1–2.5 mm long, retrorsely barbed.
