Plants 50–90 cm. Stem solitary, hollow, purplish-tinged, rough-puberulous. Basal leaves numerous, sheaths pubescent; leaf blade ovate, 3–4-pinnatisect; pinnae 4–5-paired; ultimate segments obovate-cuneate, 1.5–5 × 1–2 mm, usually 3-lobed, hispid on both surfaces. Synflorescence much branched, terminal umbel 6–9 cm across, lateral umbels 2–5 cm; bracts absent or 1–2, subulate, deciduous; rays 10–20, unequal, 1–5 cm, sparsely pubescent; bracteoles 8–12, linear-lanceolate, puberulous. Calyx teeth subulate. Petals white. Styles slender, longer than stylopodium. Fruit ellipsoid, 3–4 × 2.5–3 mm; dorsal ribs filiform, prominent, lateral ribs narrowly winged, wings ca. 1/3 width of body, thin; vittae 3–4 in each furrow, 8 on commissure. Fl. and fr. Jul–Sep.
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