Asques bisériées [75 ; 90] x [7.5 ; 9.0]µm à apex de type Hymenoscyphus, IKI+ bb, crochet+.
Paraphyses pluriseptées, cylindriques sans épaississement au somment, avec une grande vacuole réfringente (uniquement dans le dernier secteur ?).
Ascospores en fuseau [14.5 ; 15.5] x [4.0 ; 4.5]µm soit Qmoy = 3.6 avec un contenu lipidique 4-5 (2 grosses gouttes principales toujours présentes et de nombreuses plus petites autour).
Pas vu de poils ni de cellules marginales particulières.

Excipulum ectal composé de cellules en textura prismatica orientées parallèlement à la surface de la fructification.
Sous-hyménium composé de cellules en boudins (moy. 30x10µm) en textura intricata non gelifiée.
Medulla composée d'hyphes grêles et allongés (entre 3 et 4µm de large) en textura intricata gelifiée.

Avec les éléments donnés, je pense que j'ai affaire à un Ombrophila (pouvez-vous confirmer?) ; ensuite dans ma doc je ne trouve aucune espèce qui possède des spores aussi grandes et avec de telles guttules.
Merci d'avance pour vos commentaires. Les images en meilleure qualité sont temporairement mises dans le lien ci-dessous :
https://www.grosfichiers.com/QB2XtCYctCu

31/07/2022 – Ozoir-la-Ferrière (77) – France – Study on fresh living material.
On decaying twigs, under Carpinus betulinus, next to a forest pond.
Cylindrical stipitate apothecia, gregarious on substrate, white at first then greyish. Hymenium constantly convex.
Biggest specimen is 3mm diameter and 5mm tall.

Asci 8-spored inoperculate, biseriate, [75 ; 90] x [7.5 ; 9.0]µm with Hymenoscyphus-type apex, IKI+ bb, croziers+.
Paraphyses cylindrical, pluriseptate, with remarkable vacuolar body filling the entire last septum.
Ascospores fusoid [14.5 ; 15.5] x [4.0 ; 4.5]µm - Qmoy = 3.6. Oil droplets level 4-5 (2 big drops are always there, numerous smaller ones around)
No hair, no striking marginal cells.

Ectal excipulum of textura prismatica oriented parallel to the surface of the fruitbody.
Subhymenium of textura intricata non gelatinized (big cells - moy. 30x10µm)
Medullary excipulum of textura intricata gelatinized (narrow and elongated cells - width 3 to 4µm)

Those elements are leading me to the genus Ombrophila (please confirm that ?) ; then I find no suitable species in my doc with spores that long and with such an oil content.
Thanks in advance for advices, pics with better graphics are temporarily accessible through the link below (for free !) :
https://www.grosfichiers.com/QB2XtCYctCu

Pierre-Yves

Michel Hairaud, 02-08-2022 18:00

Re : Ombrophila(?) - ascospores with great oil content

Bonjour Pierre Yves, 

Content de te savoir assidu aux Helotiales ! 
Comme tu es un heureux bénéficiaire des services d'Ascomycete.org, tu as reçu récemment un superbe article de Zotto dan s notre revue, sur des espèces herbicoles d'Ombrophila. 
Regardes si cette récolte ne correspondrait pas par hasard à celle évoquée sous le nom provoisoire de O. aff. ambigua ?
C'est une espèce que nous avons récoltée en Bretagne avec Brigitte et tu trouveras une bonne planche dans l'article .
Je viens récemment de la retrouver sur Lycopus europaeus dan sune zone marécageuse (sous Salix ) et je prépare un dosssier pour avancer sur ce taxon.
Ta récolte nous intéresse .. 

Amitiés Michel

Hans-Otto Baral, 03-08-2022 09:02

Re : Ombrophila(?) - ascospores with great oil content

Good idea Michel to compare this with O. aff. ambigua. Another option would be O. rivulorum, especially HB 3066. This variable species is quite difficult and probably not homogeneous.

The apical ring of your fing, Pierre-Yves, is Calycina-like though with an annular protrusion below. Various Ombrophila species have that, but others remind more of Hymenoscyphus.

The crystals in the gelatinized medulla are well visible in your pics 1 and 4. Whether the spores finally get 3-septate and produce conidia as in my find remains to be clarified from overmature apos.

The substrate: O. rivulorum is mainly lignicolous, but there is a cf. rivulorum, 28.VII.2020 in my folder which is on a herb, maybe comparable to Michel's species with very long spores. And there are further samples on herbs. Could you please clarify the substrate in your case? Is it woody?

Michel Hairaud, 03-08-2022 09:52

Re : Ombrophila(?) - ascospores with great oil content

THanks Zotto, 
If the substrate (herb/wood) is actually differentiating, Pierre Yves 's find should not be aff. ambigua. as it is on small twigs.  

I just had a look at your file rivulorum , with several collections which may include this find. It seems the work you initiated for the genus could well be continued -:) 

Michel

Hans-Otto Baral, 04-08-2022 10:16

Re : Ombrophila(?) - ascospores with great oil content

o.k., this reddening is due to the VBs in the paraphyses.

As you wrote "Medulla composée d'hyphes grêles et allongés (entre 3 et 4µm de large) en textura intricata gelifiée", I concluded your fungus must be gelatinous. Gel is not easily demonstrable, the easiest is to check if the fungus behaves gelatinous when touched with a needle or when pressed under the coverglass.

I have no time for a study. Now when you have it dried, it is not easy to recognize an old apo for checking spore germination.

For the wood anatomy you need to photograph a clean cross-cut vertically, either by surface or transmitted light, best under around 30x or 100x.

Hans-Otto Baral, 07-08-2022 21:46

Re : Ombrophila(?) - ascospores with great oil content

Splendid indeed that you found the conidia! So only 0-1-septate when overmature.

A sheath I would not say for sure. This is better to clarufy in freshly ejected spores, while this could indeed be only ascoplasma.

The anatomy: There is almost no marrow or empty space in the centre which I would expect for herbs, this speaks for a woody plant. But I cannot recognize it.

Hans-Otto Baral, 16-08-2022 17:56

Re : Ombrophila(?) - ascospores with great oil content

No, this is not so easy. I surely wrote in the paper that both spore types are found inside mature asci and are forcibly ejected. It is a kind of heterospory.

Apart from such rather rare heterospory, in Helotiales and other groups exist principally two cases: (1) young asci are eguttulate and the spores when just formed are also, i.e. the LBs appear during spore development from young to mature; (2) young asci are multiguttulate and yung spores are also, only spore size and size of LBs increases during maturation.