Not really sure what this is so if anyone can ID it, fantastic! It was found on a boulder in the middle of a brownfield site.
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.
I usually need to rely on microscope work and/or the standard chemical spots tests for these dots-on-rocks lichens. One suggestion (guess!) is Lecidella carpathica - similar to the common L. stigmatea but with a coarsely granular thallus. Another idea is Porpidia.
I can see why Thistle has suggested Micarea lignaria. However, that species has globose apothecia and at most, those in the photo are very slightly convex at maturity.
Many thanks for all your comments, greatly appreciated.
Lat/Lng: 52.3091, -1.1545
OS grid ref: SP577682