I found this probable Cosmospora on another sordariomycete, probably Lasiosphaeria spermoides. But the perithecia of the Nectriaceae species are situated in areas of large decomposition of the Lasiosphaeria. So the actual substrate could also be the wood. It is Fagus sylvatica.

There is also a forest of an anamorph. It covers almost the entire part of the Lasiosphaeria. Possibly this is the anamorph of the Nectriaceae species.

Here are the data:

Perithecia: red, with a conspicuous papilla
Ascospores: 18-25 x 7-8 µm, 1-septate, constricted at the septum, warted, slightly unsymmetrical, tapering at both ends

Conidia: 27-33 x (6,5) 7,5-10 µm, 0-3-septate (mostly 3-septate), slightly curved

I know, that Nectriaceae are not studied sufficiently yet and hard to determine. Is there at least a working name or a species complex, where I can put this collection in?

Best regards
Steffen

Christian Lechat, 15-08-2016 05:36

Re : Cosmospora on sordariomycete?

Hi Steffen,
"Cosmospora"  is very difficult without culture and molecular data.
I think your fungus could remain in the "flavoviridis" complex and the conidia that you show are not the asexual state of a Cosmospora.
You should cultivate the ascospores of your fungus to know its asexual state.

Good luke,
Christian

Christian Lechat, 19-08-2016 05:02

Re : Cosmospora on sordariomycete?

Hi Steffen,
here is an abstract of a recent publication explaining how cultivate the ascospores.

Cultures of the living specimen were made on PDA (Potato Dextrose
Agar) with 5 mg/l of streptomycin in Petri dishes 9 cm diam. A mass
of ascospores and asci was removed from a perithecium with a fine
needle and placed in a drop of sterile water that was stirred with a
needle to distribute the elements on the slide. A part of the drop
containing ascospores was placed on PDA using a sterile micropipette,
then the Petri dish was incubated at 25°C.

Cheers,
Christian