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19-08-2022 22:26

Juuso Äikäs

A few years ago I found a group of olive-brown fru

19-08-2022 19:05

Stefan Jakobsson

On a petiole of a leaf of what seems to be Populus

09-08-2022 20:06

Stephen Mifsud Stephen Mifsud

I have found an interesting aspergillus on flowers

13-08-2022 17:18

Stephen Mifsud Stephen Mifsud

I assumed these are weak colonies of Neurospora on

18-08-2022 17:50

Thomas Læssøe

https://svampe.databasen.org/observations/10283042

10-08-2022 15:45

Pierre-Yves Julien

Récolte le 31/07/2022 – Ozoir-la-Ferrière (77)

02-08-2022 17:48

Pierre-Yves Julien

Récolte le 31/07/2022 – Ozoir-la-Ferrière (77)

16-08-2022 20:07

Bernard Declercq Bernard Declercq

Good evening,Who could be so kind to supply me fol

07-01-2014 23:04

Michel Hairaud Michel Hairaud

Bonjour à tous, Hi to all. This tiny bright yell

16-08-2022 15:50

Thomas Læssøe

https://svampe.databasen.org/observations/10283169

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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