Isolepis fluitans (L.) R.Br.

Spikelet solitary, 3–8 mm long. Nut greyish, c. 1.5 mm long. Lowest glume empty, only rarely produced into a linear lamina longer than the spikelet. Stamens 2, rarely 3. Usually aquatic, often with long narrow leaves rhizomes and culms. When on mud, the leaves are up to 1 mm wide and the culms more erect. Widespread. In water or on wet mud