Plants 1–2.5 m, aromatic. Rhizome stout, 4–5 cm thick. Stem purplish green, lower branches alternate, upper branches opposite or whorled. Basal and lower leaves long-petiolate, sheaths purple-red; blade broadly-triangular-ovate, 2–3-pinnate, pinnae all petiolulate; ultimate segments obovate or rhombic-ovate, 4–11 × 2–7 cm, 2–3-lobed, with a few coarse teeth. Umbels ca. 12 cm across; bracts 7–11, lanceolate, reflexed, scabrous, white-scarious-margined; rays 12–20, subequal; bracteoles 8–11, similar to bracts. Fruit brown, 5–7 × 3–4 mm. Fl. Jun–Aug, fr. Aug–Sep. n = 11.