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12-03-2026 16:17

Sylvie Le Goff

Bonjour à tousRécolté dans le 22 en France (ré

12-03-2026 15:45

Åge Oterhals

Dear forum,I found this small discomycete on a ver

12-03-2026 14:37

David Wasilewski

These small ascomycota (1-3 mm) ere observed growi

11-03-2026 16:48

Bruno Coué Bruno Coué

Bonjour, je serais heureux d'avoir votre avis sur

11-03-2026 17:36

Michel Hairaud Michel Hairaud

Bonjour, Je cherche des indices  pour cette réc

08-03-2026 14:05

Thierry Blondelle Thierry Blondelle

Bonjour à tous,Sur 3 récoltes supposées de H. l

09-02-2026 22:01

ruiz Jose

Hola, me paso esta colección en madera de pino, t

11-03-2026 14:14

Gernot Friebes

Hi,I would like to share a collection of Scopinell

15-09-2020 17:27

Andgelo Mombert Andgelo Mombert

Bonjour, Sur branche morte décortiquée de Berbe

10-03-2026 18:08

Marc Detollenaere Marc Detollenaere

Dear Forum,On stems of Arctium, I found some downy

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Parasite on Xanthoria parietina apothecia (arthonioid?) - Denmark Feb. 2020
Thomas Læssøe, 03-02-2020 20:28
https://svampe.databasen.org/observations/10080840

KOH gave a striking pink reaction at upper leves of the hymenium

cheers

Thomas
ps on some apothecia this fungus co-occured with Pyrenochaete xanthoriae
Alain GARDIENNET, 03-02-2020 21:19
Alain GARDIENNET
Re : Parasite on Xanthoria parietina apothecia (arthonioid?) - Denmark Feb. 2020

Hi Thomas,


It fits well with Arthonia parietinaria. Epihymenium id K+ for this species, but K- for A. molendoi.


Thus, we know (since 2016  , Fleischhacker et al.), that A. parietinaria occurs on X. parietina when A. molendoi occurs more on X. elegans.


Alain

Martin Bemmann, 03-02-2020 21:34
Martin Bemmann
Re : Parasite on Xanthoria parietina apothecia (arthonioid?) - Denmark Feb. 2020
Hi Alain, A. parietinaria was my first guess as well. But I withdrew because of the "chestnut-brown" KOH reaction stated by Fleischhacker etal:


The pink reaction observed by Thomas would fit more to A. destruens, described as "purplish violet".

However, I have no own observations.

Regards

Martin
Thomas Læssøe, 03-02-2020 21:55
Re : Parasite on Xanthoria parietina apothecia (arthonioid?) - Denmark Feb. 2020
yes, both described colour reactions a bit off from my clear pink....
Alain GARDIENNET, 03-02-2020 21:59
Alain GARDIENNET
Re : Parasite on Xanthoria parietina apothecia (arthonioid?) - Denmark Feb. 2020

Hi Martin,


Yes I noted this strange colour. But A. destruens is not given on X. parietina. Thus ascospores are bigger.


It would be good to check the reaction with next collections of Arthonia parietinaria. If I find time, I will check with mines.


Thomas, please keep it in herbarium under Arthonia sp. cf A. parietinaria.


Alain

Thomas Læssøe, 03-02-2020 23:19
Re : Parasite on Xanthoria parietina apothecia (arthonioid?) - Denmark Feb. 2020
will do and thanks :-)