Plants 40–100 cm, glaucescent throughout. Stem purplish below, striate. Lower leaves petiolate, sheaths oblong-lanceolate; primary pinnae 3–4 pairs; ultimate segments linear-lanceolate, 20–90 × 1–5 mm. Upper leaves reduced, 1-pinnate, 3-lobed or entire, sessile on expanded sheaths. Primary umbels 5–9 cm across, lateral umbels smaller; rays 4–20, 2–7 cm, unequal; bracteoles 4–9, lanceolate, ca. 3 mm, usually equal to or longer than flowers, margins membranous; umbellules many-flowered, 10–12 mm across. Fruit 3–4 × ca. 2 mm. Fl. Jul, fr. Aug.