Soft herb, often sprawling, sometimes erect; branches often tinged purple, glabrous or hairy. Leaves narrowly ovate, 1.2–6 cm long, 0.8–2 cm wide, glabrous or shortly hispid (particularly on lower surface), apex acute, margin with 4–14 serrations; petiole 0–5 mm long. Flowers in dense 3–12-flowered clusters in axils of distal leaves; pedicels much shorter than calyx. Calyx 3–5 mm long, 13-veined, densely covered with short spreading hairs, lobes up to c. as long as tube; corolla white or pink, exceeding calyx by 1–3 mm, lobes c. 1–2 mm long, the posterior one emarginate; anthers shortly exserted. Flowers Feb.–Oct.
MuM, Wim, GleP, VVP, VRiv, MSB, RobP, MuF, GipP, OtP, WaP, Gold, CVU, GGr, DunT, NIS, EGL, EGU, WPro, HSF, HNF, OtR, Strz, MonT, VAlp. Also NT, SA, Qld, NSW, ACT, Tas. Widespread through the State, usually growing on margins of watercourses and swamps, lakes etc.
