Pterygopleurum neurophyllum (Maxim.) Kitag.

Chuang and Constance (Univ. Calif. Publ. Bot. 55: 28–30. 1969) treated this species (and hence the genus) as an Asian outlier of the American genus Perideridia, but this placement remains to be confirmed.

Plants 70–100 cm. Basal leaves ovate, 10–15 × 4–8 cm; ultimate segments 20–100 × 1–3 mm. Upper cauline leaves smaller, 3-lobed or entire, sessile on expanded sheaths. Terminal umbels 3–5 cm across; peduncles 1–5 cm; bracts 5–10, linear, 3–10 × 1–2 mm; rays 6–8(–20), 2–3.5 cm, subequal; bracteoles 6–8, similar to bracts, 1–3 mm; pedicels slender, 3–8 mm, unequal. Calyx teeth lanceolate, ca. 1 mm, longer than the stylopodium. Fruit 3–3.5 × 2.5–3 mm. Fl. and fr. Sep–Nov.

Streamsides, damp areas. Anhui, Jiangsu, Zhejiang [Japan, Korea].