Bonjour ! 
Voici une planche et une photo macro d'un Asco qui nous est inconnu. Il a été récolté à Lac Beauport dans la région de Québec.
Nous croyons que ce pourrait être Mollisia ligni.

Voici les données :   
  
Date de récolte : 06 / 07 / 2009
Substrat : tige d'herbacée creuse d'un terrain vague
Ascome : 0,3-0,6 mm de diam.
Sporée non disponible

Spores étroitement et longuement ellipsoïdes, légèrement plus effilées à une extrémité, parfois très légèrement arquées, lisses, non septées, avec une petite guttule foncée à chaque pôle, 6-9 x 1,5-2 µm, 7,1 x 1,9 µm en moyenne (10 spores), Q = 3,74
Asques à 8 spores bisériées, avec crochet à la base (rare) et appareil apical amyloïde, 27-40 x 5-7 µm
Paraphyses cylindriques, un peu élargies à l'apex, à 2-3 septa, doublement ramifiées au tiers inférieur, à contenu huileux, 30-36 x 3-4 µm, dépassant les asques de 3-4 µm
Excipulum ectal et medulla en textura globulosa-angularis, constitué de cellules globuleuses à subglobuleuses, à paroi légèrement épaissie, brun olivâtre foncé en NaCl iso., jusqu'à 15 µm de diam.

Merci de nous aider, amitiés à vous tous !
Roland    

Hans-Otto Baral, 11-02-2012 08:34

Re : 50201 - Asco inconnu - Mollisia ligni ?

Difficult to say what you have. And the resolution of the posted images could be higher.

M. ligni I know only from wood. And it is characterized by inamyloid asci (though I have one collection from England on Larix with amyloid asci, which is probably something else.

I assume  you have a Mollisia, not a Pyrenopeziza. But without living paraphyss this is difficult to be sure.

Cpuld you please send me the plate in higher resolution? You figure the spores as almost eguttulate but th two asci on th upper right contain spores with large guttules I think. Did you test these also with iodine? They look like a Helicogonium (intrahymenial parasite). If this is true they should be inamyloid.

Zotto
(zotto@arcor.de)

Hans-Otto Baral, 11-02-2012 17:38

Re : 50201 - Asco inconnu - Mollisia ligni ?

Thanks Roland wfor the higher resolution (I noticed that it is no problem now to add larger images in Ascofrance).

I am quite sure that the asci with big oil drops are a parasite (Helicogonium trabinelloides probably). You can easily test this by adding iodine to such asci - they must be inamyloid.

It is a pity that the collector has no microscope, as I understood, and cannot have a look at the fresh sample. So I cannot exclude a Pyrenopeziza here, especially since the substrate is herbaceous. The Helicogonium makes a Pyrenopeziza even more probable, as I use to see it as a parasite in this genus.

Perhaps the first record for N-America of this Helicogonium.

Zotto

Hans-Otto Baral, 11-02-2012 20:33

Re : 50201 - Asco inconnu - Mollisia ligni ?

Excuse me please, Roland, this parasite is unusual: it forms only asci, and that in the hymenium of discomycetes. So the ascus with the spores with oil drops is a Helicogonium, and the ascus on the upper right with amyloid pore belongs to the presumed Pyrenopeziza.

This parasite may occur inn all apothecia of your collection, or only in some of them. If you are unlucky, you will not detect it again. But f you detect it once more, then please test Lugol for the apical ring, it should be negative.

If you wish to read I can send you my paper on Helicogonium. But it is 11.5 MB

Zotto

Hans-Otto Baral, 12-02-2012 22:03

Re : 50201 - Asco inconnu - Mollisia ligni ?

Voilá! Tres bien. I fully agree

Zotto

Hans-Otto Baral, 17-02-2012 18:28

Re : 50201 - Asco inconnu - Mollisia ligni ?

Bernard Declercq made a comprehensive key on the genus. Maybe he reads this and will answer you. But it is also on the DVD.

Zotto