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 globose, bony or softer utricle, each inflorescence comprising 2
racemes, a sessile female, and a pedunculate 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 flat on back, keeled, winged above, upper glume
boat-shaped. Caryopsis subglobose to ellipsoid.