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.
It looks similar to descriptions of Lobaria species, possibly Lobaria pulmonaria. May be worth using the 'Search iSpot' panel to see if other identifications match your lichen.
On the mainland this is almost always on trees, but L. pulmonaria does seem happy on rock-faces, often sea-cliffs, out on the islands.
This was actually growing on an old gravestone.
Isle of Skye
Lat/Lng: 57.0963, -5.8666
OS grid ref: NG658072