On coastal rock in the company of Hydropunctaria (Verrucaria) maura. Photo 1: fungal infection or competition with H. maura?
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 have seen this black material overgrowing both C. thallincola and C. microthallina, and as it has seemed external to the Caloplaca and cortical in nature, I have assumed it is the Hydropunctaria fighting back.
There are fungi that attack Caloplaca of course. Last week I found C. ruderum on a church wall near Lincoln, looking unhealthy and with many of its apothecia blackened. I shall sort out what it is and put it on my site one of these years.
Lat/Lng: 56.184241, -2.808492
OS grid ref: NT499993