In the forest I was sure of the substrate. Now I have some doubts. Alnus also performed nearby. Although I still think that this piece of wood did not belong to Alnus, now I have some doubts.
If it was actually Alnus, I would probably suggest Eutypella cerviculata, if it is Eutypella at all?
Although for me, this genre is a bit mysterious. In "Neuere Aufsammlungen stromatischer
Pyrenomyceten aus Österreich, insbesondere
der Steiermark "- Von Larissa N. VASILYEVA, Alnus is given as the substrate. In turn, the same author in the work" Pyrenomycetes of the Great Smoky Mountains National Park. III ", mentions Betula sp as a substrate
Therefore, it can be suspected that this species is not attached to one host? ... perhaps also occurs on Tilia?

Does anyone have a more detailed description of this species? This data that I found about this genre is very general.

 

Mirek

I was wondering between Valsa and Eutypella. However, among Vals I did not find a species similar to mine.
I found a more detailed description of this species in "Pyrenomycetes germanici. Die kernpilze Deutschlands bearb." The species described in this work as Valsa cerviculata. (on Carpinus)

I am also wondering about the similarity of Eutylella atropae. This species is included in the key "TAXONOMIE ET NOMENCLATIJRE
DES DIATRYPACEES À ASQUES OCTOSPORES "I" "??
I found a more detailed description of this species (as Sphaeria atropae) in Exploration scientifique de l'Algérie [Vol. I] ". Unfortunately, I can't read Latin with comprehension.
Mirek