Hi friends,

I have some Corylus twigs here with a deformation caused by small, black pyrenomycetes, which are growing on the deformations, while the twig is still living.

Pseudothecia 0,2-0,35mm, 1/2 embedded into the surface and growing freely later, black, pyriforme, smooth, without ostiolus.
Spores are 20-24x8-10µm, asymmetrical, upper cell broader, generally with three septations, smooth, hyaline. Asci with 8 spores, somewhat saccate, broadest in the middle-lower region, IKI- (red), bitunicate, no stalk, 55-65x17-22µm, without pseudoparaphyses/periphyses. Wall consisting of a 12-15µm thick region of dark brown parenchymatous cells and a ~10µm thick region with paler to hyaline, compressed cells.

Any idea? I thought about Leptosphaerulina, but I did not find any species with the described features.

regards,
björn