Growing on a pretty unhealthy tree in RSPB reserve.
Caution: Do NOT use iSpot to identify fungi to eat!
Some fungi are very poisonous so a mistaken ID could have serious consequences.
No interactions present.
Very unusual shape almost cup-like not the usual cushion shape.
this is not white brain your second picture shows this clearly as a spreading respunite not as a coalesce or fusing of adjacent fruitbodies.
All given ID's are subject to error/ommissions. Please seek independent verification before acting on ANY advice given. BE SAFE =)
Lat/Lng: 51.5459, -2.9613
OS grid ref: ST334834