Plants 60–200 cm. Stems usually purple-spotted, sometimes uniformly purple, usually solid, sometimes hollow near bases, glabrous proximally to densely puberulent throughout, glandular-puberulent distally. Leaves in (3s–)4s–5s(–6s); petioles 5–20 mm, glabrous or pubescent; blades pinnately veined, lance-elliptic to lanceolate or lance-ovate, mostly (6–)8–23(–30) × (1.5–)2–7(–9) cm, bases gradually or abruptly tapered, margins sharply serrate or doubly serrate, abaxial faces gland-dotted and densely pubescent to glabrate, adaxial faces sparingly hairy or glabrous. Heads in flat-topped, corymbiform arrays. Involucres often purplish, 6.5–9 × 3.5–7 mm. Phyllaries glabrous or densely pubescent. Florets (8–)9–20(–22); corollas purplish, 4.5–7.5 mm. Cypselae 3–5 mm. 2n = 20.
Damp thickets, meadows, shores etc, usually on rich or calcareous soils; at elevations up to 2,500 metres.