Bonsoir Elisabeth,
Une hypocréale toute mignonne.
Il faut que tu bannisses le nom de Nectria pour ce type de récolte. De nos jours on sait ce qu'est une Nectria stricto sensu. En plus, visiblement tu as affaire à une Bionectriacée.
Peut-être à chercher vers le genre Bryonectria. Assurément ce n'est pas Trichonectria hirta, étant donné les spores.Bonne recherche,
Alain

Bonjour Alain,

Ce n'est certainement pas Trichonectria hirta. Je pensais plutôt à l'espèce ci-jointe.

Elisabeth

Oh excuse moi, j'avais oublié l'existence de ce "Nectria" hirta, car Nectria hirta est aussi le basionyme de T. hirta.  En effet ce taxon créé par Peter Döbbeler (je suis d'ailleurs étonné de son  choix de l'épîthète) est assez proche de ta trouvaille.
Toutes ces hypocréales bryophiles mériteraient d'une étude approfondie basée sur le séquençage moléculaire.  Même Trichonectria hirta n'est pas dans le bon genre.

Hi Elisabeth,

That is a nice find. I have never seen bryophilous Nectria s.l. on Orthotrichum affine. This fungus is also similar to several species of Bryocentria. It would be interesting to better visualise the ornamentation in lactophenol cotton blue if possible but they do look striated.

If they are indeed striate, it may be related to 'Nectria' racovitzae, seen here http://ascofrance.fr/search_forum/74646. The hairs are similar but not identical.

Another similar species with striated ascospores is Nectria sanramonensis Döbbeler, Brenesia 37:145 (1993) but this is tropical with larger spores.

Peter Döbbeler's Nectria hirta = N. salisbergensis. The ascomata are white and tiny in this so I don't think they match. The surface of the ascomata also lacks hairs from the specimen I have seen.

So it may be something new; maybe Peter would know.

All the best,
George

Bonsoir George,

Je n'ai jamais trouvé une telle espèce sur Orthotrichum. Les fructifications sont recouvertes de poils blanchâtres, sur les photos elles étaient humides et donc cela ne se voyait pas bien.

Chez N. racovitzae, les spores finement striées sont bien visibles, mais chez cette espèce, il est plutôt difficile de les photographier. J'ai aussi pensé à Bryocentria, mais je n'ai pas trouvé d'espèce.

Elisabeth

Bonsoir Elisabeth,

To me, the most similar species in Bryocentria is B. hypothallina. Most features are similar, though the spores are a little narrow and ornamentation differs. This is not to mention the obvious host differences, B. hypothallina being strongly necrotrophic, and the fact that B. hypothallina ascomata are leaf-perforators and not superficial like in your collection. 

Of the (described) European species that form superficial ascomata on mosses, there is only B. septinensis and B. cyanodesma, and yours is clearly neither of these.

N. mnii (Döbbeler, 1978) is superficially similar but has glabrous ascomata.

Did you notice if the host was dying or did it seem mostly healthy?

I would say to query with Peter as he would probably have an inclination and perhaps be keen to examine if there is a good amount of material. Please let me know if you find out more. I will keep an eye open on this host myself now in Britain.

Thanks and all the best,
George

An update on this that we have published these collections as the new species, Bryocentria insolens. Thanks to Elisabeth for making these nice collections available, and François for finding it in Belgium. Peter Döbbeler had actually found it decades ago in Switzerland but it was not described. We put all the collections together and also provided some molecular data for most of the European species of the genus. If anybody is interested, the paper is here: https://pfsyst.botany.pl/-Bryocentria-insolens-Hypocreales-a-new-bryophilous-ascomycete-on-Lewinskya-and-a,205550,0,2.html

Finally, thanks to AscoFrance as the forum enabled the study.

All the best,
George

Dear George,

Thank you for this message. I am very pleased that this successful work has now been published! I also think your collaboration was great .

Arnold Büschlen

Many thanks Georges for the thorough study of the group and sharing  this very interesting paper and of course to Elisabeth and other finders. 

It seems that interest for bryophylous fungi is clearly growing among mycologists 
Amitiés. Michel