Carex pseudocyperus Hop Sedge C DD N
I look for this sedge in ponds - it likes to grow actually in the water rather than just in boggy or damp ground like most sedges. It is one of the taller sedges and can reach up to almost a metre in height with very long leaves.
This sedge is found in southern England, sometimes in eastern Wales, dotted here and there in Ireland but is uncommon in Scotland.