Perennial, submerged herbs.
Shoots erect, subtended by 2 elliptic or ovate scales. Rhizome creeping,
herbaceous, monopodial. Leaves 1-4, alternate, flattened, linear, entire,
3-veined, margin toothed at apex, leaf-sheath 1-6 cm l ong, compressed, bi-auriculate, ligulate. Flowers axillary to
leafy bracts. Male flowers : consisting of 2 unequally inserted anthers
attached to the axis, filament absent, pollen filiform. Female flowers
subsessile, style simple, undivided. Fruitlet achene-like, laterally
subcompressed, globose to ovoid, beaked,
with bony pericarp.