Is it not amazing that flowering plants can grow in our most hostile, dry habitats and everywhere down to thriving in the running water of streams and rivers? What is basically the same botanical structure can produce so many small variations to make almost any habitat a home. From navelwort growing out of walls to the river water crowfoot (Ranunculus fluitans) and countess other specialisms in between.
The problems of surviving in running water should not be underestimated, even for a plant. Firstly, of course, they have to make sure they have a firm anchor hold in the river bottom. Then, they need to present as little resistance to the water as they can and so they are hairless on their stems and leaves and the leaves are long and thin. Finally, if the flower is to be pollinated it has to appear above the water's surface on a stout, strong stem able to resist the water's flow.
All of these features can be seen in the river water crowfoot. To aid its survival it tends to find areas of the river where the water is moving more slowly on the shelter at the inside of bends in the river and normally at the lower reaches of the river where it has widened out and the flow is less vigorous than upstream.
There are several water crowfoot species, each adapted for life in different forms of water from ponds and large lakes, to ditches and to fast flowing chalk streams.