Plants 50–150 cm tall, robust. Root fusiform. Stem solitary, branched with spreading hairs. Basal and lower leaves pinnate, ca. 40 × 30 cm; pinnae 2–3 pairs, broad-ovate, ovate-oblong, pinnatifid, adaxially appressed puberulent, abaxially densely grayish puberulent, base subcordate, oblique, margins serrate. Upper leaves reduced, sessile, sheaths broad-ovate, leaf blade 3-lobed. Peduncles 10–17 cm, terminal umbels ca. 20 cm wide; bracts absent; rays 20–30, unequal, 6–11 cm, glabrous or sparsely pubescent inside; bracteoles 4–7, linear, nearly as long as pedicels, to 13 mm. Calyx teeth triangular, minute. Petals white, outer flowers in umbels radiant, enlarged petals broadly obcordate, deeply lobed. Fruit obovoid, 8–10 × 5–7 mm, glabrous or sparsely puberulent; vittae solitary in each furrow, clavate, extending to 2/3 length of mericarp, 2 on commissure, 1/2 length of mericarp. Seed face plane. Fl. Jul–Aug, fr. Aug–Sep.