or perennial, monoecious grasses, culms erect or decumbent, sometimes floating.
Leaf-blades broad, ligules short. Inflorescence many in upper leaf-axils, each
subtended by a glogose, bony or softer utricle, each inflorescence comprising 2
racemes, a sessile female, and a peduncullate male, subtended by a prophyll.
Female spikelet : lower glume broader; upper glume narrower; lower floret
reduced; upper floret hyaline; both florets staminate. Male spikelets : glumes
subequal; lower glume, margins keeled; upper glume boat-shaped. Caryopsis
subglobose to ellipsoid.