26-11-2025 18:13
The entire run of Mycotaxon is now available throu
25-11-2025 14:24
Thomas Læssøehttps://svampe.databasen.org/observations/10490522
25-11-2025 11:03
Mick PeerdemanHi all,One of my earliest microscopy attempts, so
24-11-2025 15:23
Arnold BüschlenHallo, auf einer offenen Kiesfläche am Rande ein
23-11-2025 11:16
Bohan JiaHi, I found small discs growing on dead stem of
21-11-2025 10:56
Christopher Engelhardt
Very small (~0,5 mm) white ascos, found yesterday

Bonjour chers collègues,
aujourd'hui j'ai ramassé un Nectria s.l. sur Hypoxylon fragiforme, que m'etonne par ces charactèrs que je ne connais pas (ce que ne veut dire beaucoup, car je connais des Nectrias assez mal ....)
Les spores sont assez petit, appr. 8-10 µm de longeur, verruculeuse.
C'est pas Nectria episphaeria, parce-que les perithecia ne sont pas papillé, mais avec une sommet applati.
Voici des impressions sur cets perizhecia.
peut quelqu'un me donner un piste pour cet espèce, ou me instruire que je doit examiner en plus?
merci beaucoup,
Andreas
I bet this fungus is Cosmospora arxii. The apex of the perithecia does puzzles me a bit, though. The perithecia of specimens that I have seen of C. arxii have had blunt apices. I think it must be a morphological variant of the same species. You can confirm the identity of the fungus by isolating it into pure culture. It should have a salmon-pink colony on potato-dextrose agar.
Best,
Cesar Herrera
Dear Cesar,
thank you very much for your tentative identification.
Unfortunately I have no possibility to make a pure culture of it. Is there something else to verify the identification? How certain is it that I can put the name arxii to it?
thank you again,
Andreas
Hi Andrea, hi Cesar.
Cesar, could you send me a complete description of C. arxii please.
This fungus is very current in our countries.
Alain
Andreas, if you want I can try a culture from your specimen. I am interested because there are two species occuring on H. fragiforme. One with a pink-salmon colony and another with a green colony.
Regards,
Christian


