Looks like this is not so rare – confirmed by Brian Douglas Kew in Norfolk and now in Crymlyn Bog South Wales. 5 hours on Bog (more correctly fen) Monday 22nd August found on Cladium mariscus in boggy woodland and open fen -not easy terrain!
Photo (USBx20) also shows parasitic asco – Eudarluca cariscis (Brian’s id). I’m getting out of my depth here not just in Bog!