Plants 20–60 cm tall. Stem slender, branching, glabrous rarely sparsely puberulent. Basal leaves pinnate; pinnae 5–6 pairs, broad-ovate to ovate-oblong, 2–3 × 1–2 cm, margin pinnatifid to pinnatisect. Cauline leaves similar to the basal, reduced upward with strongly expanding sheaths; pinnae lanceolate, glabrous or finely pubescent. Bracts 3–5, linear; rays 4–15, subequal, 3–4 cm, densely hairy with spreading hairs; bracteoles 3–5, linear, nearly as long as umbellule; flowers 15–20 per umbellule. Calyx teeth conspicuous, unequal. Petals white. Fruit ovoid, 6–8 × 4–5 mm, pilose; lateral ribs broadly winged; dorsal vittae filling the furrow, 3/4 length of mericarp, lateral vittae sometimes shorter, commissure vittae narrower than dorsal. Fl. and fr. Jul–Sep.