Prostrate perennial, stems to c. 40 cm long, rooting at nodes. Leaves shortly petiolate, opposite, lamina orbiculate to ovate, 1–3.5 mm long, 0.5–3.5 mm wide, glabrous except for a few scattered sessile glands. Flowers solitary or sometimes paired in leaf axils; sepals c. 5 mm long, ovate or deltoid-ovate, virtually free, green, sometimes with dark streaks; petals ovate, c. 15 mm long, spreading, yellow, sometimes with small red dots. Capsules not seen. Flowers Dec.–Feb.
VVP, GipP, Gold, HSF. Also naturalised NSW, Tas. Native to Eurasia, occasionally encountered on wet banks of drainage lines and other water bodies with other invasive species. Collected from Millgrove near Warburton (2000) and Ballarat (2004).