Centre photo by Jonathan Micheal
Short, dense spikes of pink flowers, flower spikes often solitary.
Two forms - aquatic or terrestrial. Long-stalked leaves, round or truncate at base. Floating leaves hairless, larger than those of terrestrial plants. Stems creeping, rooting at nodes. Long rhizomes. Spreads by seed and rhizome fragments.
Widespread. Aquatic form found in ponds, lakes, ditches, slow-flowing rivers.
Terrestrial form on damp ground, marshes, wet fields, dune-slacks.
Photographs above: Aughinish, County Limerick. August 2008