Found in/near the edge of a freshwater loch, surrounded by acid heath in Islay, Western Scotland.
No interactions present.
Thanks for the ID! My field notes were too scribbly to decipher and I'd had little success keying from photos. Before i-spot I'd have been stuck!
Stace 3rd ed. lists this as Eleogiton fluitans, formerly Isolepis fluitans or Scirpus fluitans. Phylogenetically, could be amalgamated with Isolepis but morphologically distinct.
Lat/Lng: 55.7, -6.2
OS grid ref: NR3859