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Hallo, ich habe in einer Moos-Aufsammlung (epiphy

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"Hello everyone,I'm relatively new to microscopy (

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Lothar Krieglsteiner Lothar Krieglsteiner

.. found by a seminar-participant, I do not know t

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Malcolm  Greaves Malcolm Greaves

This Helvella was in mixed woodland. Uniform cupul

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Lothar Krieglsteiner Lothar Krieglsteiner

20.6.25, on branch of Abies infected and thickened

16-03-2014 22:00

Ralph Vandiest Ralph Vandiest

Hello,I found this species a few months ago but ha

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https://svampe.databasen.org/observations/10572899

07-12-2025 22:43

Andreas Millinger Andreas Millinger

Good evening, tried to determine with Munks Valsa

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Pyrenomycete with hyaline non-septate spores
Marcus Yeo, 03-07-2014 21:46
This pyrenomycete was growing on a fallen branch of a broadleaved tree.

Perithecia are black, superficial, ca 250 µm diam, with a more or less smooth surface. Some have a small inconspicuous papilla.


Asci are cylindrical-clavate, gradually narrowed to base, 80-90 x 8-9 µm. They are 8-spored, irregularly biseriate. The apical ring is visible as 2 small dots (IKI negative).


Paraphyses are abundant.


Spores are hyaline, straight or slightly curved, 17-22 x 3.5-5 µm. They are 0-septate, though sometimes appearing 1-septate in KOH. In water large OBs are present.


I have struggled to identify this specimen. I've wondered about something in the Lasiosphaeriaceae or Trichosphaeriaceae but haven't got any further than that. Using Munk the closest match seems to be Trichosphaeria melanostigmoides but I'm not convinced this is correct, e.g. the spore shape doesn't look quite right.


I'd be very grateful for any help.


Marcus

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Jacques Fournier, 03-07-2014 22:20
Jacques Fournier
Re : Pyrenomycete with hyaline non-septate spores
Hi Marcus,
it looks like a Chaetosphaeria, a genus where a safe identification at species level most often requires the anamorph. Apparently the anamorph is not visible on your first photo. Maybe you can find it around the colony.
Good luck,
Jacques
Marcus Yeo, 03-07-2014 23:15
Re : Pyrenomycete with hyaline non-septate spores

Jacques


Thanks for your suggestion. I'd ruled out Chaetosphaeria because the spores of my specimen appear to be consistently without septa - possibly the spores aren't fully mature? I didn't notice an anamorph associated with the perithecia but I'll have another look.


Marcus


 

Alain GARDIENNET, 04-07-2014 11:20
Alain GARDIENNET
Re : Pyrenomycete with hyaline non-septate spores

Hi friends,


Apparently ascospores are uniseptate. You can see that feature with observation in Melzer.


Alain

Marcus Yeo, 04-07-2014 11:38
Re : Pyrenomycete with hyaline non-septate spores
Alain - you may be right!

Some spores appear to be 1-septate in KOH and in MLZ but I wasn't certain. It looked as if this might just be an artefact caused by the way in which the oil bodies had dispersed. I will take another look.

Marcus
Marcus Yeo, 06-07-2014 22:24
Re : Pyrenomycete with hyaline non-septate spores
I have some more observations on this specimen.

I've looked at spores in Melzers and I believe they lack septa at first, but become 1-septate in the ascus.


I also found an anamorph associated with some of the perithecia. It has brown, unbranched, septate conidiophores, ca 125-160 x 4-5 µm. Conidia are borne terminally on short, slender hyaline stalks. They are obovoid; 16-19 x 11-14 µm; 2-septate, with a small hyaline basal cell and 2 large brown cells.


The anamorph appears to be a Brachysporium, either B. obovatum or B. britannicum. This would indicate that the teleomorph belongs to the genus Cryptadelphia, which seems a reasonable fit. Using the 2004 paper by Reblova & Seifert, C. obovata is a possibility. However, the ascospores of my specimen are generally longer and narrower than the description of C. obovata, and the colour and width of the conidia don't seem to fit B. obovatum (the anamorph of C.obovata). The anamorph of my specimen seems to fit the description of B. britannicum – Reblova & Seifert state that teleomorphs for B. britannicum have not been discovered.


So perhaps I'm making progress towards an identification. Any views would be welcome.


Marcus

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Chris Yeates, 06-07-2014 22:37
Chris Yeates
Re : Pyrenomycete with hyaline non-septate spores
I agree, Marcus - I would say Brachysporium britannicum. My experience with species in this genus is that they are often opportunistic and not clearly associated with adjacent fungi.
Best wishes
Chris
Jacques Fournier, 07-07-2014 08:54
Jacques Fournier
Re : Pyrenomycete with hyaline non-septate spores
Hello Marcus and Chris,
this is a nice and conclusive investigation.I will keep Cryptadelphia in mind!
As to the use of Melzer to see the septa when they are blurred by spore contents, I sugest to just keep the slide overnight and let the reagent clear off the contents and show even the most delicate septa.
Cheers,
Jacques
Marcus Yeo, 07-07-2014 23:01
Re : Pyrenomycete with hyaline non-septate spores

Chris & Jacques


Thank you both for your help.


Marcus