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26-04-2026 21:08

William Slosse William Slosse

Several species of Ramularia occur on Rumex that I

22-04-2026 20:54

Enrique Rubio Enrique Rubio

Hi to everybody.This Pyrenopeziza grew in moist le

25-04-2026 11:34

Louis DENY

Bonjour forumdans la clé de Zotto, L. pudicellum

24-04-2026 03:16

David Chapados David Chapados

Found while looking at something else from wood in

22-04-2026 01:06

Richard VALERI Richard VALERI

Bonjour à tous.Je vous présente cette Nectria s.

22-04-2026 20:17

Marian Jagers Marian Jagers

Is anyone familiar with the Hyphomycetes genus Pse

23-04-2026 06:46

François Freléchoux François Freléchoux

Bonjour, Voici la description d'un minuscule asco

21-04-2026 22:14

Margot en Geert Vullings

This cup fungus was found on April 10, 2026, on lo

22-04-2026 19:12

Louis DENY

Bonjour forum.Trouvé à Belfort, est de la France

21-04-2026 21:00

Sylvie Le Goff

Bonjour à tousJe sollicite votre aide pour cet as

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Dermea(?) on Alnus
Gernot Friebes, 02-06-2015 12:49
Hi,

I'm assuming this is a Dermea but I couldn't find a fitting species. It grew on the bark of a dead Alnus tree. What's striking is that the asci are "4-spored", because 4 spores are aborted early and only 4 spores mature. The ascospores measure about 20.1–24.4 x 8.5–9.7 µm and the asci measure about 116.3–140.0 x 15.9–20.0 µm. Unfortunately I didn't have Lugol readily available while studying this fungus (shame on me!) but at least in Melzer's reagent the asci are negativ, however it seems like the apical apparatus is slightly stained by the Melzer's (just no amyloid reaction).

Any ideas?

Thank you and best wishes,
Gernot
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Hans-Otto Baral, 02-06-2015 13:00
Hans-Otto Baral
Re : Dermea(?) on Alnus
Hi Gernot

I hope it is not true that you used MLZ. But it seems so, because Pezicula frangulae reacts deeply red in Lugol. - Sorry, now I read the reason for using MLZ. O.k., nice example how Melzer's is misleading.

How sure are you with Alnus?

Zotto
Gernot Friebes, 02-06-2015 13:27
Re : Dermea(?) on Alnus
Hi Zotto,

yeah, I forgot to bring my Lugol and only had Melzer's available. :-/ Had I used Lugol I probably would've realized it's a Pezicula rather than a Dermea but as it were the dark apothecia lead me towards Dermea. I guess that's what you get for using Melzer's!

As for the substrate, I know that Frangula was also present but from what I've seen only as much smaller trees... But it could be possible that the substrate was indeed Frangula.

Thanks for your help and best wishes,
Gernot
Hans-Otto Baral, 02-06-2015 16:07
Hans-Otto Baral
Re : Dermea(?) on Alnus
You can verify the substrate: Frangula is distinctly ring-pored though with small pores. Alnus is scattered-pored, also it has characteristic scalariform perforations (leiterförmig).
Gernot Friebes, 02-06-2015 20:29
Re : Dermea(?) on Alnus
I only have rather thin pieces of wood that I cut off with the bark but I tried to make a few sections. I put a piece of millimeter paper into the photos to provide some sort of scale. Is it possible to say something with these photos?

Best wishes,
Gernot
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Hans-Otto Baral, 02-06-2015 21:22
Hans-Otto Baral
Re : Dermea(?) on Alnus
Prima! Definitiv kein Alnus, aber sehr gut passend zu Frangula alnus! Schön ringporig.
Gernot Friebes, 02-06-2015 21:42
Re : Dermea(?) on Alnus
Sehr schön, dann passt das ja!

Danke nochmals!

Schöne Grüße
Gernot