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13-09-2025 14:10

Wim de Groot

We found this hymenoscyphus on rubus fruticulosis.

13-09-2025 15:43

Edmond POINTE Edmond POINTE

Bonjour Christian,J'ai trouvé deux spores ressemb

11-09-2025 16:57

Jason Karakehian Jason Karakehian

Our revision of Marthamycetales (Leotiomycetes) is

13-09-2025 14:01

Thomas Flammer

dark brown apothecia, splitIKI-Spores biguttulate

10-09-2025 23:53

Marcel Heyligen Marcel Heyligen

Found on Robinia pseudoacasia together with Diapor

10-09-2025 17:18

Blasco Rafael Blasco Rafael

Hola, encontre este estiercol de vaca estos apotec

02-09-2025 11:34

Thomas Læssøe

https://svampe.databasen.org/observations/10527903

07-09-2025 08:19

Josep Torres Josep Torres

Hello.Tiny pinkish discomycetes, photographed and

09-09-2025 12:07

Edmond POINTE Edmond POINTE

Bonjour amis mycologues,Trouvé sur moquette de ch

08-09-2025 19:07

ruiz Jose

Hola me pasan esta recolecta en madera de fraxinus

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Mycosphaerangium tetrasporum ?
Arold Lavoie, 27-04-2014 06:48
Arold LavoieBonjour,

J'aimerrais savoir si selon vous, il s'agit bien de Mycosphaerangium tetrasporum? Voici mes observations :
Apothécie : érumpante dans le bois; disque brun orangé à noir; environ 1 mm de largeur
Asque : 4 spores. Après KOH et solution de Lugol, les asques deviennent rouges entre les spores.
Spores : subglobuleuse, granuleuses, hyalines lorsque jeunes, devenant brun foncé à maturité; 26,2 - 29,8 um de long.
Habitat et substrat : Branche de feuillu au sol. Érablière à hêtre et à chêne rouge. Montérégie, Québec.

Bien que Seaver (1951) rapporte des spores entre 20 et 25 um de long, Cash (1940) mentionne plutôt 22 – 28,5 um de long, ce qui le rapproche de mes mesures.

Voici les liens vers mes photos :
https://www.flickr.com/photos/gnomediscret/14028500055/
https://www.flickr.com/photos/gnomediscret/14025311071/
https://www.flickr.com/photos/gnomediscret/14028948084/
https://www.flickr.com/photos/gnomediscret/14005391336/
https://www.flickr.com/photos/gnomediscret/14025303382/
https://www.flickr.com/photos/gnomediscret/14028513015/
https://www.flickr.com/photos/gnomediscret/14028939934/

Je vous remercie!
Arold Lavoie, 27-04-2014 08:20
Arold Lavoie
Re : Mycosphaerangium tetrasporum ?
Et quelqu'un aurait ce document svp?

Verkley, G.J.M. 1999. A monograph of the genus Pezicula and its anamorphs. Studies in mycology. Vol. 44. 180 p.

Metci!
Hans-Otto Baral, 27-04-2014 10:06
Hans-Otto Baral
Re : Mycosphaerangium tetrasporum ?
Very interesting collection! I see strong similarities to Hymenobolus agaves, a species we had here in the forum. Maybe both are congeneric?

I think it is this species, but I did not compare the other two transferred there by Verkley. 

Zotto
Arold Lavoie, 27-04-2014 17:25
Arold Lavoie
Re : Mycosphaerangium tetrasporum ?
Dear Zotto!

I read the description in Verkley (thanks for sharing!) and it confirms the identification. The only difference I see is that he wrote that the asci are IKI-. The asci on my specimen are clearly IKI+ red, but I've made a pre-treatment with KOH... 

Thank you vey much!
Hans-Otto Baral, 27-04-2014 20:47
Hans-Otto Baral
Re : Mycosphaerangium tetrasporum ?
No, they are IKI-. The iodine reaction of asci refers always to the wall, not the ascoplasm. In your case the ascoplasm reacts red, which indicates the presence of glycogen.

You say that there is Quercus and Fagus around, Didi you look at the broken wood? The distinction is very easy: only Quercus is ring-pored (rapidly visible with a hand lens).

Zotto
Arold Lavoie, 27-04-2014 22:59
Arold Lavoie
Re : Mycosphaerangium tetrasporum ?
I identified the substrate this afternoon. It's a broken branch of Northern red oak (Quercus rubra), a species close to Q. coccinea (on which Ellis made his collect in 1875).

Thanks for the information about the red asci!