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.
GleP, Brid, VVP, GipP, WaP, CVU, EGL, WPro, HSF, OtR, VAlp. Also WA, SA, Tas. Widespread across southern Victoria where it favours swamp margins and other perennially wet sites.
