Description from Flora of China
Angelica rivulorum Diels, Notes Roy. Bot. Gard. Edinburgh 5: 288. 1912; Pterocyclus rivulorum (Diels) H. Wolff.
Plants 50–100(–150) cm. Root stout, dark brown, 1–2 cm across, aroma strong, like that of Angelica or Apium. Stem to 1 cm thick at base, thinly ribbed, branching. Basal petioles 7–16 cm; sheaths oblong; blades 1–2-ternate/pinnate; ultimate segments broadly ovate, 5–11 × 4–8 cm, setose along nerves, regular-serrate, apex acute to acuminate, base cordate. Stem leaves gradually reduced upwards; uppermost with inflated, often bladeless sheaths. Umbels 8–10 cm across; peduncle 15–25 cm; bracts 3–4, linear-lanceolate, 2–4 × 0.2–0.4 cm; rays 15–20, 4–7 cm, scabrous; bracteoles 6–8, linear-lanceolate, 1–2.5 cm, greenish-white with dark green median stripe.; pedicels 14–20, 8–10 mm. Calyx teeth inconspicuous. Petals greenish-white, obcordate, ca. 3 mm. Stylopodium conic. Fruit dark brown, ovoid-oblong, 8–10 × 4–6 mm; ribs all narrowly winged; vittae 1 in each furrow, 2 on commissure. Fl. Aug, fr. Aug–Sep. 2n = 22*.
This species is used in Yunnan as a regional substitute for the medicine “qiang huo” (Notopterygium franchetii and N. incisum).
Damp grasslands, gravelly stream banks, frequently collected; 3100–4000 m. NW Yunnan.