Plants 40–80 cm, slender. Stems decumbent, scarcely branched, rooting at lower nodes. Leaves mostly reduced, 1-pinnate, fistular; pinnae few, remote on the rachis, subulate, 5–15 × 0.5–1 mm. Umbels 1.5–3 cm across; peduncles elongate, 5–8 cm; bracts absent, or occasionally 1, linear, 0.5–2.5 cm; rays 4–8, 0.5–1.5 cm, unequal, sometimes pubescent; bracteoles 3–5, linear, 3–3.5 × ca. 0.5 mm, unequal; umbellules 15–20-flowered; pedicels 2–3 mm, unequal. Calyx teeth ca. 0.6 mm. Styles ca. 0.6 mm. Fruit ovoid, ca. 2 × 1.5 mm; dorsal and intermediate ribs protruding, filiform. Fl. Jun–Jul, fr. Aug–Sep.

Moist places at forest margins, alpine marshlands, wet meadows, streamsides; 2500–4600 m. W Sichuan, S Xizang, NW Yunnan [Bhutan, India, Nepal].