Description from Flora of China
Anethum japonicum (Thunberg) Koso-Poljansky.
Plants stout, (30–)40–70(–100)cm, essentially glabrous. Stem often flexuous. Leaf blade broadly ovate-triangular, to 35 × 25 cm, thinly coriaceous, 1–2-ternate; leaflets ovate-orbicular, 3-parted, 7–9 cm broad, glaucous; central segments obovate-cuneate, lateral segments oblique-ovate. Umbels (4–)5–10 cm across; bracts 2–3 or absent, ovate-lanceolate, 5–10 × ca. 2 mm, pubescent; rays 15–30, 1–5 cm, unequal, puberulous; bracteoles 8–10, linear-lanceolate, equaling or longer than flowers; umbellules ca. 20-flowered. Calyx teeth obsolete. Petals purple or white, abaxially hispidulous. Styles short. Fruit oblong-ovate or ellipsoid, 4–6 × 2.5–4 mm, hirsute, especially on dorsal ribs; lateral ribs winged, wings very thick; vittae small, 3–5 in each furrow, 6–10 on commissure. Fl. Jun–Jul, fr. Aug–Sep.
Coastal areas, seashores; below 100 m. Fujian, Hong Kong, Jiangsu, Shandong, Taiwan, Zhejiang [Japan, Korea, Philippines].