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31-03-2026 21:18

Miguel Ãngel Ribes Miguel Ángel Ribes

Good evening. oes anyone have the original descrip

31-03-2026 20:57

Stefan Blaser

Hello everybody, I hope somebody can help me with

26-03-2026 15:31

Ãke Widgren Åke Widgren

Hello,I found this one in October last year, on r

31-03-2026 16:20

Mlcoch Patrik Mlcoch Patrik

Hello, Please about help with determination. On

31-03-2026 08:19

Bernard CLESSE Bernard CLESSE

Bonjour à toutes et tous,Pourriez-vous m'aider à

30-03-2026 12:18

Sylvie Le Goff

BonjourRécolté sur la base de Pteridium aquilinu

30-03-2026 12:03

William Slosse William Slosse

Hello all,On 27/03/26, in Kraaiveld in Wingene (Be

25-03-2026 10:35

Hulda Caroline Holte

Hello,I collected this species growing on a dead b

28-03-2026 17:41

Louis DENY

Bonjour forum,Mollisia trouvée sur tige de Molini

30-03-2026 09:53

Yanick BOULANGER

BonjourVoici des petites fructifications poilues s

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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
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  • message #17147
  • message #17147
  • message #17147
  • message #17147
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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