Waterside plant for ID please

Waterside plant for ID please

Observation - Waterside plant for ID please - UK and Ireland. Description: Three different plants here all growing in the same location, the path between the two ponds at Cannop. I hope that they are all the same species. There was a lot of colour variation but they all seem to have the same habit. Thanks for looking.

Three different plants here all growing in the same location, the path between the two ponds at Cannop. I hope that they are all the same species. There was a lot of colour variation but they all seem to have the same habit. Thanks for looking.