Annuals or perennials, often aquatic; culms commonly ascending from a prostrate base. Leaf-blades linear to lanceolate or ovate. Inflorescence an open or contracted panicle. Spikelets 2-flowered, with the florets similar or dissimilar, the lower male or bisexual, the upper female or bisexual; rhachilla disarticulating below each floret; glumes falling soon after the florets, subequal, two-thirds to as long as the spikelet, membranous; lemmas elliptic-oblong to orbicular, obscurely 5-7-nerved, obtuse, the lower similar to the upper or larger and thinner, the upper chartaceous to thinly coriaceous; stamens 3. Caryopsis ellipsoid to suborbicular, dorsally flattened on one side.