Parmelia sulcata observed on a twig on an oak tree.
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.
This isn't Parmelia sulcata.
Its probably either Parmotrema perlatum or Hypotrachyna revoluta / affrorevoluta but the photo doesn't show necessary details sufficiently clearly.
Lat/Lng: 52.3921, -2.3557
OS grid ref: SO758771