dioecious, stemless, stoloniferous herbs. Leaves basal, sessile, linear or
strap-shaped, 3-9 veined. Male flowers numerous, minute, clustered and enclosed
by common spathe, finally breaking free and floating on water surface, sepals
3, two larger than the other, petals 2 or 3, minute, stamens 1-3. Female
flowers solitary in spathe, spathe tubular, apex bifid, pedunculate, peduncles
long, coiled after anthesis, sepals 3, petals 3, minute, ovary with numerous
ovules, styles 3, bifid. Fruit cylindric or triangular-cylindric, included in
the spathe. Seeds numerous, oblong or fusiform.