Hi,

a few days ago I collected a corticated branch of Prunus avium with an unknown pyrenomycetous fungus (soc. Hymenochaete corrugata). The ascomata are black, rather soft, and often very closely accompanied by algae. I also oberved some algal cells inside the ascomata which might suggest that it is a lichenized species. The ascomatal wall also shows a distinctive greenish-brown colour. The asci appear to be bitunicate and are IKI-, the hamathecium consists of very dense, frequently septate and inflated hyphal cells, and the ascospores measure about 49–65 x 4–5 µm and are multi-septate. 

Thanks for any ideas!

Best wishes,
Gernot