Plants (60–)120–180 cm, glabrous throughout. Stem solitary, slender, usually flexuose, paniculate-branched, lower branches alternate, upper branches verticillate. Basal leaves petiolate; blade broadly ovate-triangular, 3–4-pinnatisect; ultimate segments ovate-oblong, often pinnately parted or lobed, lobules lanceolate, 2–4 mm, both surfaces glabrous. Upper leaves reduced, bladeless, sheaths lanceolate, embracing. Terminal umbel short-pedunculate, lateral umbels 1–3, simple or opposite, exceeding terminal; bracts absent or 1–3, linear, small; rays 7–11, 2.5–3 cm, subequal; bracteoles 4–5, lanceolate; umbellules 7–15-flowered. Stylopodium low-conic. Fruit pale brown, oblong or oblong-obovate, (7–)10–15 mm; lateral broadly winged; vittae (1–)3–4 in each furrow, 4–8 on commissure. Fl. and fr. Jun–Jul.
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