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26-10-2025 13:39

Joaquin Martin

Hi,I found this fungus in a mixed forest of spruce

27-10-2025 10:05

Tripodi Mario

Hello everyone,on October 25th, 2025 I found this

27-10-2025 00:34

Francois Guay Francois Guay

I found this strange species in Québec,Canada, gr

26-10-2025 21:23

Juuso Äikäs

Hello, a couple weeks ago I found some pale, whit

26-10-2025 12:01

Louis DENY

Hello forum,Trouvé à Belfort (400m) sur tige her

23-10-2025 20:59

Patrice TANCHAUD

Bonsoir, est-ce que quelqu'un posséderait un com

24-10-2025 14:50

Riet van Oosten Riet van Oosten

Hello, Found by Laurens van der Linde, Oct. 2025

24-10-2025 03:11

Francois Guay Francois Guay

I found this fungus growing on decaying conifer wo

20-10-2025 09:36

Nicolas VAN VOOREN Nicolas VAN VOOREN

Hello.I'm searching for the following article:Bene

07-09-2025 08:19

Josep Torres Josep Torres

Hello.Tiny pinkish discomycetes, photographed and

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Hypoxylon on Quercus robur bark
Enrique Rubio, 20-01-2012 18:45
Enrique RubioHi to all:

I have collected this Hypoxylon species that grows on Quercus robur bark, at 150 m of altitude, with pulvinate, coalescent and purplish grey stromata. KOH extractable pigments are chlorinaceous-olive. Asci IKI and Mlz. blue. Ascospores with a spore-lenght, straight to sigmoid, germ slit. Perispore dehiscent in KOH 10%.
The stromata seem to have ochraceous granules just beneath the surface.

Maybe Hypoxylon porphyreum or only an Hypoxylon fuscum?.
Many thanks again for help me
Enrique
  • message #17147
  • message #17147
  • message #17147
  • message #17147
  • message #17147
  • message #17147
Yannick Mourgues, 20-01-2012 19:10
Yannick Mourgues
Re : Hypoxylon on Quercus robur bark
Bonjour. Entre les deux, ma préférence irait vers Hypoxylon porphyreum.
Par contre, sur mon écran, la couleur de la réaction dans KOH sur ta photo est jaune ? Qu'en est-il vraiment ?
Yannick
Enrique Rubio, 20-01-2012 19:37
Enrique Rubio
Re : Hypoxylon on Quercus robur bark
Bonsoir Yannick:
La couleur du papier est ocracée mais avec des nuages olive aussi. Il nèst pas jaune pure.
Enrique
Jacques Fournier, 20-01-2012 20:46
Jacques Fournier
Re : Hypoxylon on Quercus robur bark
Hola Enrique,
it is hard to tell but H. porphyreum might indeed be the best match. The KOH reaction appears yellow because it is recorded on paper, on which the yellow fraction migrates first, it is in fact a basic chromatography. On your photo the colour just around the fragment of stroma is brownish, more in agreement with can be expected from H. porphyreum. I suggest you try to record the coloured reaction in a drop of KOH on a slide on a white background, the result should be easier to interpret.
If you have enough material I would be happy to see it, thanks!
Cheers,
Jacques
Enrique Rubio, 22-01-2012 19:07
Enrique Rubio
Re : Hypoxylon on Quercus robur bark
Merci Jacques. Je vais t'envoyer un petit morceau de mon récolte. Mais il tres petite.
Merci de ton aide
Enrique