Cladium mariscus Great Fen-sedge C DD N
This is a tall sedge which prefers base rich boggy areas and lakesides. It can be up to 2 metres tall and has leaves with hard serrated edges hence its other common name: Saw Sedge or Sawtooth Sedge.
Quite common in Ireland this plant is found at sites dotted about in England, Scotland and Wales with reasonable concentrations only in north west Scotland and east Anglia.