or perennial, floating or rooting in substrate, rootstock thick, roots fibrous,
stems short or creeping. Leaves mostly rosulate, petioles distinct, sometimes
inflated, leaf-blade lanceolate to broadly ovate. Inflorescence of raceme or
panicle, usually subtended by a spathe-like leaf-sheath. Flowers bisexual,
mostly regular or rarely irregular,
variously coloured. Perianth usually 6, petaloid. Stamens 3 or 6, rarely
1, unequally adnate to perianth-tube or base of perianth-lobes, filaments free,
anthers 2-celled, introrse, dehiscing by vertical slits, or rarely by pores.
Ovary superior, 3-locular and placentation axile, or unilocular with parietal
placentation, style 1, stigma capitate or minutely 3-lobed. Fruit a 3-valved
capsule. Seeds longitudinally ribbed.