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 am not sure about this. I agree there is a parasitic fungus there, and maybe it is Xanthoriicola in its early stages, but there are other things that grow in the apothecia of Xanthoria.
Microscope work needed.
You have given this 'observation' the name of the possible pathogenic fungus but have not said it is the fungus that is of interest, or named the host.
So sooner or later, some bright spark will come along, not having read the related observations, and "correct" this to Xanthoria parietina. Might be an idea to edit the text of the initial observation?
That was a good point!
What are the other fungus possibilities in Xanthoria apothecia?
Several, but I haven't extracted a list as yet. Sorry.
Lat/Lng: 51.7, -9.0
OS grid ref: SK1826