Lichenicolous perithecia on Myriolecis (Lecanora) albescens

I was pleased to see details of this putative/probable Phaeospora lecanorae posted here and endorse Paul Cannon’s suggestion. If Paul D. thinks it is the closest match then I think it is worth going with that suggestion, running it by Brian Coppins and, unless he has hesitation (I doubt he will) claiming P. lecanorae as new to Britain.

In this twitter thread I explain how my confidence was boosted in my suspicion of Acarospora versicolor and how I added it to the British list:

https://twitter.com/obfuscans3/status/1369957066455023617

It is not a total disaster if a taxon gets added to the British list and we subsequently find out it is something else. It has happened many times before. As just one example British material of Caloplaca marmorata were previously called C. lactea until Czech lichenologists helped me with the taxonomy of this species. We try hard to verify our identifications but sometimes we can be over-cautious. If we didn’t accept your specimen as Phaeospora lecanorae, the alternative would be to put it unnamed (or only named to putative genus) into the database (with a brief description) and this may make it more difficult for people to refer to your occurrence in future. My intuition would be to add it to the British list as P. lecanorae but Brian’s opinion will be far more important than mine.

If you need any further help with this, do contact Paul or me as it is well worth pursuing.

Mark

I added an arguably more contentious lichenicolous fungus to the British list, Cladosporium licheniphilum:

https://fungi.myspecies.info/all-fungi/cladosporium-licheniphilum

Again it was a suggestion by Paul Diederich, and from memory a less definite endorsement by him than for the Phaeospora lecanorae. Paul Cannon by contrast, reasonably suggested that it might just be a generalist saprobe. In discussion with Brian Coppins, and having found it on Xanthoria parietina several times, we decided to add it to the British list. The true identity of this hyphomycete that occasionally turns up on X. parietina is almost certainly still in doubt but we now recognise it as an entity, have a description of it available and can submit records of it to the database. If we are calling it by the wrong name it won’t be a disaster. The BLS database would be amended to reflect any new insights.