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19-04-2026 21:23

Steve Clements

Bonjour, I found this anamorphic fungus on old pl

19-04-2026 20:46

Steve Clements

1 mm diameter approx spherical conidiophores on pl

12-04-2026 17:56

Hardware Tony Hardware Tony

Found on dead stems in February earlier this year

17-04-2026 19:16

Enrique Rubio Enrique Rubio

Hi to everybodyI would appreciate any assistance r

14-04-2026 05:32

Ethan Crenson

Hi all, A few weeks back a friend pointed out som

17-04-2026 15:14

Bruno Coué Bruno Coué

Bonjour.Récoltes du 16/04/2026, sur feuilles mort

12-04-2026 15:52

Gernot Friebes

Hi,I'm looking for help with this anamorph collect

14-04-2026 21:52

Gernot Friebes

Hi,found on dead leaves of Carex elata. Conidia: 4

16-04-2026 22:09

Buckwheat Pete

Hello, I'd like to ask about this older specimen:

15-04-2026 19:33

Fátima Durán Manzaneque

Hi!! I need help, I found this Ascomycete but I d

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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