Here is a photograph I took a couple of days ago of a river plant called Chalkstream Water Crowfoot. It was floating near the surface of a narrow stretch of river close to where I photographed the lichen. I love the vibrant green colour of the leaves.
I must thank the following website for helping me identify this plant. It looks very useful for finding names of other wild flowers and plants in the UK too as it has photographs of each part of the plant: