Plants 8–50 cm. Rhizome tuberous to long conic, 1–3 × 0.5–1 cm. Stem solitary, thinly ribbed, little-branched. Basal leaves petiolate, petioles 4–8 cm, sheaths short, narrow; blade semi-orbicular or broad-triangular in outline, 1.5–3.5 × 2–5 cm, 3-lobed or 3-foliolate; ultimate segments ovate to obovate, 1–2.5 × 0.8–2 cm, base cuneate, incised-serrate distally, adaxially purple-green, abaxially dark purple. Upper stem leaves conspic-uously heteromorphic; ultimate segments becoming linear, 15–75 × 0.5–5 mm, entire. Umbels 4–9 cm across in flower (to 12 in fruit); peduncles (2–)4.5–10 cm; bracts and bracteoles ab-sent; rays 5–12, (0.8–)1.5–6 cm, unequal; umbellules 9–18 mm across, 7–12-flowered; pedicels 5–15 mm, unequal, slender, scabrous along one side; rays and pedicels elongating and spreading in fruit. Calyx teeth conspicuous, narrow-triangular, ca. 0.3 mm. Petals white, greenish-white or purple, ovate or ovate-lanceolate, 2–3 × ca. 0.5 mm; apex linear, ca. 1 mm, pa-pillate-hairy abaxially. Fruit subovoid, ca. 2 × 2 mm. Fl. Aug–Oct, fr. Sep–Nov.