Rhizomatous perennial, glabrous apart from glandular hairs on inflorescence; stems stout, soft, hollow, erect, to 100 cm high, 2–6 mm diam., tinged with purple, bearing racemes at most nodes. Leaves sessile, elliptic to lanceolate, 2–7.5 cm long, 2–15 mm wide, apex acute, slightly amplexicaul, margins entire or finely toothed. Racemes 5–15 cm long, c. 15–30-flowered; peduncle mostly 1–3 cm long; fruiting pedicels spreading, 1.8–4 mm long, shorter than bracts. Calyx-lobes 1.8–3.5 mm long, 1–2 mm wide in fruit; corolla 1.8–3 mm long, pale pink or mauve. Capsule ovate or c. circular, 2–3 mm long, 2–3 mm wide, often slightly broader than long, slightly emarginate, not strongly compressed; style 1–1.5 mm long. Flowers summer.
GleP, VVP, VRiv, WaP, Gold, HSF. Also naturalised SA, NSW, New Zealand. Native to Europe and Asia. In Victoria restricted to the far south-west from Mt Eccles to the mouth of the Glenelg River; in running water and on stream banks or marshy ground.
