Erect or prostrate biennial to 1 m high, stems ribbed. Leaves 1- or 2-pinnate, upper leaves reduced; lamina to 6(–15) cm long; leaflets 3–7, ovate-cuneate, to 5 cm long, often deeply 3-lobed and lobes again divided; margins crenate to toothed; petiole longer than lamina. Umbels 1–4 cm diam., shortly pedunculate, occasionally more or less sessile; rays 3–12, unequal, 1–3(–6.5) cm long; umbellules 3–10(–20)-flowered; pedicels to 5 mm long. Petals c. 0.5 mm long, white, often with reddish midrib. Fruit broad-ovoid, c. 1.5 mm long; mericarps with 5 slender, pale ribs. Flowers Oct.–Feb.