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.
The spreading nature of the thallus suggests that to me. It would have rhizines.
X. ulophyllodes was what I'd originally hoped when I found it but I can't find any sign of rhizines - and the presence of apothecia on this and the other specimens on the same tree seems to probably rule out X. ucrainica
Lat/Lng: 50.7, -2.1
OS grid ref: SY9691