My last riddle was solved so fast I have to ask another one :)

Substrate: On dead twig of cf Sorbus on the bark

Macro: Bark with small, blackish bumps of 0.3 mm diam. Aside from this blackened surface, no clear delimitation of perithecia was visible. A very small pore was just visible in some of the bumps.

Micro: Asci cylindric, with short stalk, 85-95 x 16-18 µm. Spores hyaline, two-celled, usually with one cell slightly broader/bigger, constricted at septum, usually 1 or 2 large oildrops per cell, 18-19.5 x 6-7 µm . Spore surrounded by a slime sheath. (I have also observed some spores that are brownish and "warted": mature or just degrading?). Covering layer is formed of plant tissue which is intermingled with dark brown hyphae (see photos).

Thank you for any comments

Stefan

Alain GARDIENNET, 08-07-2013 09:50

Re : Black bumps on bark

I agree with Walter, it's very closed to A. analepta.

This fungi is often recorded by lichenologist on bark of  different trees (Labbbaumen).
But there are several species and it's not always easy to give the right name.
Have you seen a thallus ? And what is the width of paraphyses (s.l.) ? 
The last picture is in KOH ? 
Alain