23-04-2024 15:18
Lothar Krieglsteiner
... but likely a basidiomycete. I hope it is o.k.
23-04-2024 13:17
Edouard Evangelisti
Bonjour à tous, Je viens de récolter ce que je
23-04-2024 21:49
Ethan CrensonHello all, A friend recently found this orange as
22-04-2024 11:52
Zuzana Sochorová (Egertová)
Hello,I made a loan of a collection of Microstoma
11-01-2022 16:36
Jason Karakehian
Hi does anyone have a digital copy of Raitviir A (
22-04-2024 20:38
Miguel Ángel Ribes
Good afternoon.Does anyone know this anamorph?It g
19-04-2024 14:28
B Shelbourne
Cudoniella tenuispora: Distinctive macro and habit
20-04-2024 16:02
Michel Hairaud
Bonjour,On me fait part, pour diffusion d une list
Puzzling pyrenomycete
Chris Yeates,
17-10-2020 20:29
Bonsoir tous
I recently collected, on a decorticated Quercus branch, numerous tiny black ascomata. They are up to 120µm in diameter and very flattened - i.e. not globose. While appearing smooth under the microscope there are short stout setae (less than 20µm long.).
The spores are uniseriate in the lower part of the asci, but clustered/biseriate towards the apex. In the living state they are mostly biguttulate and measure 6.4-8 x 2.7-3.1µm; in strong IKI the VBs break down and the older spores show a (true?) septum and the fact that they are clearly thick-walled.
Again in IKI the asci do not show a consistent apical apparatus - there is no blueing, in some cases what looks like a Diaporthales-type apex can be seen (see image) but nothing is visible in living material.
I can't even start to place these in an order and would welcome any suggestions.
Amitiés, Chris
Paul Cannon,
20-10-2020 18:34
Re : Puzzling pyrenomycete
Hi Chris
As no-one has suggested a name for this, I'll venture a suggestion.
It's difficult to see any details of the ascomata from your images (they need to be dry...) but I would look in and around Nitschkia. The genus Acanthonitschkea differs from Nitschkia [both genus spellings are correct, by the way] by the presence of spines on the ascomata/subiculum. However, yours are very small and inconspicuous and it could therefore be a short-spined species of Nitschkia with these being overlooked by previous authors. These things happen...
N. confertula might fit your collection, possibly, but there are other options. See Nannfeldt, Stray studies in the Coronophorales (Svensk Bot Tidskr. 69: 289, 1975), also Huhndorf et al. (Mycol. Res. 108: 1834, 2004) - I can send you if needed.
Good luck!
Paul
Chris Yeates,
20-10-2020 20:55
Re : Puzzling pyrenomycete
Thanks for the comments Paul.
Both the spores, and their arrangement in the asci are, I agree, similar to that one sees in Nitschkia and its allies. However, something I didn't mention in my original post was that the perithecia were thin-walled (no risk to cover-slips!), unlike Nitschkia, and, although black were slightly transparent. I know several of the species in that genus - including N. confertula (see attached). Also the perithecia were at most half the minimum diameter cited for all the likely Nitschkiae. The material is now dried and I shall have another look at it in due course.
Cheers, Chris
