Plants on the border or even submerged! 49

Let's collect plants spending their life in the water or on the border - in the swamps, bogs, marshes, which need high level of water to survive. Which will die if we meliorate everything and build banks made of stone. Please, do not publish: - epiphytic cacti, - plants in a vase, - plants adorned with droplets of spring rain, - and other ideas not in the scope of view of this group. Good luck wading along the border! Many thanks to all colleagues for the wonderful collection of observations!