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14-04-2026 05:32

Ethan Crenson

Hi all, A few weeks back a friend pointed out som

14-04-2026 21:52

Gernot Friebes

Hi,found on dead leaves of Carex elata. Conidia: 4

14-04-2026 20:31

Gernot Friebes

Hi,can this be Psilachnum lateritioalbum on Phragm

12-04-2026 17:56

Hardware Tony Hardware Tony

Found on dead stems in February earlier this year

12-04-2026 15:52

Gernot Friebes

Hi,I'm looking for help with this anamorph collect

12-04-2026 12:22

William Slosse William Slosse

In a dune grassland in Oostduinkerke (Belgium), on

11-04-2026 15:45

Zuzana Sochorová (Egertová) Zuzana Sochorová (Egertová)

Please, could anyone send me this paper?Moyne G.,

11-04-2026 13:34

Artem Ptukha

Hello, I am seeking assistance with the identific

11-04-2026 10:42

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Pyrenomycete with yellow subiculum on Aralia
Ethan Crenson, 14-04-2026 05:32
Hi all,

A few weeks back a friend pointed out some yellow fuzz in small cavities in stems of Aralia (A. elata or A. spinosa). I saw some depauperate perithecia among the fuzz. So I put the stem in a moist chamber for a couple of weeks. 


A pyrenomycete has since grown.  There are some small necks, fully covered in the same yellow subiculum. The subiculum turns brown-orange in KOH. This seems to be a Dothidiomycete. But if I am wrong about that, it is a Sordariomycete with a very thick unitunicate ascus and a 

Asci IKI-, 174-224 x 13.7-17µm. 

Pores brown, muriform with mostly 3 transverse septa and 2 or more longitudinal septa. 13.3-20.5 x 9.7-11.5µm

Paraphyses narrow.  

Any help would be appreciated.

Thanks,

Ethan
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Jacques Fournier, 14-04-2026 10:42
Jacques Fournier
Re : Pyrenomycete with yellow subiculum on Aralia
Hi Ethan, nice little thing!
as usual with pyrenomycetes, a first critical step is to assess whether asci are uni-or bitunicate.
I say critical because it is often not easy to clearly assess.
IKI is not diagnostic but Congo red or coloured inks may be useful to understand the ascus apex anatomy.Judging from your photos the apex is not thickened but appears to be topped by a ring-like structure that would possibly stain in Congo red, heated if necessary.
If positive, this reaction would strongly suggest Sordariomycetes rather than  Dothideomycetes and I suggest you to look into Thyridium, there is a recent paper by Sugita & Tanaka doi: 10.3897/mycokeys.86.78989 which might helpful.

All my best,
Jacques
Ethan Crenson, 14-04-2026 19:22
Re : Pyrenomycete with yellow subiculum on Aralia
Hi Jacques,

Thank you for your help.  I had considered Thyridium at first before the ascus anatomy confused me.  

I have a feeling you are right about Thyridium, but in order to gain some experience with the microscopy I tried Congo Red (1% aqueous solution) and then I tried it again after heating and long soak (again 1% aqueous). Results are in the photo below.  

I didn't get a lot of contrast, but there is something there that I am comparing to the illustration from the illustration in the Kendrick book I have. And of course it seems to align with the image in the Sugita and Tanaka paper you suggested:


More to come once I have looked at the paper.

Ethan
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Jacques Fournier, 15-04-2026 15:04
Jacques Fournier
Re : Pyrenomycete with yellow subiculum on Aralia
Hi Ethan,
thanks for your excellent images.They indeed show an apical ring like structure, refractive, unstained in CR but contrasting against the pale red ascus scontent. 
Positive or negative stain in CR is abviously an informative feature, in connection with the chemical nature of  the ring. And it supports the lead toward Thiridium and not toward Dothideomycetes. Apical rings do occur in a few genera (like Delitschia for example) of the latter class but uncorrelated with the other features of your collection.
Good luck!
Jacques