Aquatic or semi-aquatic perennials, with usually tall culms. Leaf-blades linear to narrowly lanceolate, flat, deciduous; ligule a ring of long or short hairs. Panicles large, dense, profusely branched, silkily hairy, bearded at the bases of the lowest branches. Spikelets 3-11-flowered, the lowest floret male or barren, the following bisexual, the uppermost ± reduced; rhachilla bearded above with long silky hairs; glumes 3-5-nerved; lemmas narrow, rounded or slightly keeled on the back, glabrous; lowest lemma much longer than the glumes, 3-7-nerved, ± persistent; fertile lemmas acuminate, 1-3-nerved; stamens 3, or 2 in the lowest floret.