Description from Flora of China
Pleurospermum longipetiolatum H. Wolff; P. pilgerianum Fedde ex H. Wolff; P. rockii Fedde ex H. Wolff.
Plants 40–70 cm. Root conic, branched. Stem hollow, ribbed, base 5–12 mm thick. Basal and lower leaves long-petiolate, sheaths narrow-oblong; blades ovate, 7–18 × 5–15 cm, 3-ternate-pinnate; pinnae 5–7 pairs, proximal pinnae petiolulate; ultimate segments oblong-lanceolate, 10–25 × 2–5 mm, hirtellous along nerves and margins otherwise glabrous, irregularly incised. Leaves gradually reduced upwards. Terminal umbels fertile, 8–17 cm across, peduncle 2–4 cm, overtopped by the sterile lateral umbels (when present), peduncles to 14 cm; bracts 8–12, oblong-ovate to spatulate, 1.5–3 cm, broadly white-margined to the first lobes, apex 3–5-lobed; rays 12–28, 3.5–7 cm, unequal, smooth; bracteoles 8–10, oblong-elliptic to spatulate, 10–15 mm, apex entire or shortly 3-lobed; pedicels numerous, 6–10 mm. Calyx teeth obsolete. Petals obovate, white, ca. 1 mm. Anthers dark purple. Stylopodium short-conic. Fruit oblong-ovoid, 4–6 × ca. 3 mm; dorsal ribs sinuolate-winged, lateral ribs plane-winged; vittae 1 in each furrow, 2 on commissure. Fl. Jul–Aug, fr. Sep.
This species is similar to, and sometimes treated as conspecific with, Pleurospermum davidii (here a synonym of P. benthamii). It is here distinguished by the more finely divided leaves (ultimate segments to 5 mm wide), hirtellous along the margin, the smaller fruits (less than 6 mm), and the terminal umbel overtopped by the staminate lateral umbels. It has reputed medicinal value (in Sichuan).
Alpine grasslands, river banks; 2500–4300 m. Gansu, Hubei, Ningxia, Qinghai, Shaanxi, Sichuan.