Plants 30–130 cm. Caudex simple. Stem solitary, rigid, branching from the middle, solid, acute-ridged, deeply fluted, nodes puberulent or glabrous. Leaf blade broad-elliptic, 5–18 × 4–10 cm, 3-pinnatisect; ultimate segments linear-lanceolate, 3–15 × 1–4 mm, margins narrowly revolute, apex apiculate. Synflorescence much-branched; umbels 2–7 cm across; peduncles hirsute; bracts absent, occasionally 1–5, subulate or linear, ca. 4 × 0.2 mm; rays 8–20, 1–2.5 cm, inner faces and bases hispid; bracteoles 8–14, linear, ca. 1.5 × 0.1 mm, margins pubescent; umbellules 15–30-flowered; pedicels 1–5.5 mm. Calyx teeth triangular or lanceolate, ca. 0.5 mm, pubescent. Petals white, abaxially puberulent. Fruit oblong-ovoid, slightly dorsally compressed, 2.5–3.5 × ca. 1.5 mm; lateral ribs slightly broader than the dorsal; vittae 3–4 in each furrow, 6 on commissure. Fl. and fr. Jul–Oct.