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01-06-2025 09:37

Charles Aron Charles Aron

Hi All, I found this Octospora growing with liver

06-07-2025 19:36

Castillo Joseba Castillo Joseba

me mandan el material de Galicia (España) recolec

05-07-2025 12:38

Åge Oterhals

I found this pyrenomycetous fungi in pine forest o

04-07-2025 20:12

Josep Torres Josep Torres

Hello.A fungus growing on the surface of a trunk o

20-06-2025 08:33

Josep Torres Josep Torres

Hello.Small, blackish, mucronated surface grains s

28-06-2025 16:00

Josep Torres Josep Torres

Hello.A tiny fungus shaped like globose black grai

04-07-2025 12:43

Castillo Joseba Castillo Joseba

me mandan el material seco de Galicia (España) 

03-07-2025 18:40

Castillo Joseba Castillo Joseba

me mandas el material seco de Galicia (España) re

03-07-2025 20:08

Francois Guay Francois Guay

I found this interesting yellowish asco growing on

01-07-2025 23:37

Josep Torres Josep Torres

Hello.A Pleosporal symbiotic organism located and

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Peziza arvernensis or something else?
Carmel Sammut, 05-05-2015 17:16
A medium sized Peziza, identified as P. arvernensis, but when examining a recent collection I noted some differences which may or may not be important. The specimens (2 collections, different years) were collected one on decomposing branches (Quercus ilex?) and one on soil (buried wood?). The flesh is 2mm thick, under a hand lens 3 layers can be seen - the dark subhymenium, a clear centre and a dark ectal excipulum. Under a microscope 5 layers can be made out, excluding asci & paraphyses.
The subhymenium (layer 5 in Donadini) consists of a narrow layer composed of a mix of textura intricata with elements of t. globosa-angularis. Medullary excipulum is made up of 3 distinct layers. The upper layer (layer 4) is wide (600µm) and made up of textura globosa with some cells reaching 175µm in diameter. The middle med. excipulum (layer 3) consists of a narrow layer (220µm) of t. intricata with some globular elements reaching 50µm diameter. The lower med. excipulum (layer 2) consists of a wider (250µm) layer of t. angularis (some elements up to 70µm wide). The ectal excipulum (layer 1) is a dark coloured layer (360µm thick) composed of t. intricata.
Asci 280 x 13µm, pleurorhynchus base. Paraphyses slightly inflated at the tips (6 - 9µm), septate, hyaline. Ascospores Mean 17.2 x 10.2µm; Qe = 1.69, ellipsoid, hyaline, eguttulate, rough (but no specific ornamentation seen with CB not with oil immersion unfortunately; when examining images, at high contrast, one can see a central oil drop which is not visible normally - perhaps an artifact of my setup.

The species appears somewhere between arvernensis and pseudosylvestris (particularly the wide upper med.excipulum) but P. pseudosylvestris is not a European species. Donadini separates the 2 species by the very wide 2 & 4 layers which this collection appears to have, but the spores do not show particular ornamentation. Has anyone collected P.arvernensis which such wide layers?

  • message #35604
  • message #35604
Nicolas VAN VOOREN, 05-05-2015 17:25
Nicolas VAN VOOREN
Re : Peziza arvernensis or something else?
The "central oil drop" is the nucleus of the spore.
P. arvernensis has clearly verrucose ascospores, so it's important to check this character.
Carmel Sammut, 05-05-2015 17:31
Re : Peziza arvernensis or something else?
Thank you Nicholas. Unfortunately I do not have a good oil immersion lens. The following image was taken with a x600 lens and shows the spores with lactophenol CB.
  • message #35606
Nicolas VAN VOOREN, 05-05-2015 17:52
Nicolas VAN VOOREN
Re : Peziza arvernensis or something else?
After these pictures, I don't believe that the ascospores are verrucose (like those of P. arvernensis). So it could be simply P. varia.
Carmel Sammut, 05-05-2015 17:58
Re : Peziza arvernensis or something else?
Thank you Nicholas.
I had not considered P. varia as the middle t. intricata should be visible as a distinct layer.

I forgot to post a TS section before. In the attached image there is no distinct middle layer, but I have never seen P. varia, so I may be wrong.
  • message #35611
Carmel Sammut, 06-05-2015 15:14
Re : Peziza arvernensis or something else?
Using a different key I came up with P. domiciliana (Medardi - Ascomiceti d'Italia) or P . granulosa/granularis (Spooner - Online updated key) but many keys do not include the flesh makeup so I doubt any of these is correct.
Andreas Gminder, 06-05-2015 17:40
Andreas Gminder
Re : Peziza arvernensis or something else?

Hello,


 


in contrast to Nicolas I do believe that the spores are verrucose. In my opinion the smooth spores of Peziza varia agg. are withour any content and are completely smooth. the shown spores do have something inside or on the spores. I believe it is an ornamentation.


 


best regards,


Andreas

Carmel Sammut, 06-05-2015 17:49
Re : Peziza arvernensis or something else?
Thank you Andreas for your opinion.
The spores do not appear to be smooth. Varying the focus there seems to be some roughness on the surface but maybe because I did not use oil immersion it is difficult to be certain. Even if the spores are verrucose the medullary excipulum width is rather large for P. arvernensis. This was the reason for my post, as this is the first time I found this species I wanted to have opinions on what to look for to get a more confident identification.