Light grey crustose lichen on concrete slab.
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 isn't Lecidella elaeochroma as that is a species only found on bark or timber.
could it be a Verrucaria species?
Lat/Lng: 49.6, 11.1