Perennial aquatic or semi-aquatic herb, procumbent; stems soft, smooth, glabrous, 10–60 cm long, rooting at nodes. Leaves alternate, ovate, pinnatifid or pinnatisect, 20–55 mm long, 20–40 mm wide, glabrous; lobes 1–2 mm wide; bracts leaf-like, trifid to pinnatifid, 5–20 mm long; bracteoles linear, 0.4–0.6 mm long, entire, brown. Inflorescence (1–)3–11-flowered; pedicels 0.4–0.5 mm long; sepals 2, green, triangular, 0.8–1 mm long; petals 2, green to red, 1.7–2.9 mm long; stamens 4; ovary 2-celled, ovoid, slightly compressed, 1.1–1.3 mm long, styles 2, stigmas shortly fimbriate. Fruit compressed-ovoid, 1 to 5 per axil, 2.8–3.1 mm long, 2.2–2.7 mm diam., pale greenish-brown; margins muricate, undulate, sometimes weakly winged. Flowers Oct.–Feb.