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17-09-2025 19:43

Lachnellula suecica ?
Philippe PELLICIER

Sur branche morte de Mélèze. Les ascospores sphÃ

18-09-2025 08:35

Chaetomium
Edmond POINTE Edmond POINTE

Bonjour amis mycologues,Trouvé sur moquette de ch

17-09-2025 16:14

Sepultaria ?
Philippe PELLICIER

Apothécies enterrées, fermées au début puis s'

17-09-2025 10:50

Ascomycete on Polystichum proliferum
Heather Merrylees

Hi there!I am hoping for any advice on the identif

11-09-2025 16:57

Marthamycetales revision published
Jason Karakehian Jason Karakehian

Our revision of Marthamycetales (Leotiomycetes) is

16-09-2025 12:53

Encoeliopsis rhododendri
Philippe PELLICIER

Pézizes de 1-4 mm, brun grisâtres, sur les capsu

03-09-2025 12:44

Ascolichen on Blechnum?
Enrique Rubio Enrique Rubio

Hi to somebody.I would like to know your opinion o

15-09-2025 14:40

Engler & Prantl, Nat. Pflanzenfam. (Ed. 2) 1938
Nicolas VAN VOOREN Nicolas VAN VOOREN

Hello.I'm searching for a digital copy of the seco

14-09-2025 22:16

Cheilymenia stercorea
Philippe PELLICIER

Apothécies petites jusquà 3 mm, oranges, avec de

13-09-2025 14:01

Otidea platyspora or something else?
Thomas Flammer

dark brown apothecia, splitIKI-Spores biguttulate

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Roseodiscus ?
Nigel Chadwick, 27-02-2021 19:00
Hello

I am hoping for some advice about a discomycete I found on a moorland hill in Lancashire, England at c. 450m, on peat amongst bryophytes - mainly Ceratodon purpureus. I am out of my depth here because I usually study lichens, but I have considered Bryoscyphus, Discinella, Octospora and Ombrophila before finding myself at Roseodiscus formosus.


A rough description:
Apothecia pale pink, 2-5mm diameter with ± flat disc, tapering to a whitish stipe (overall height 3-4mm). Paraphyses c. 2µm wide, septate, not expanded toward their apices, sparsely branched. Asci c. 8µm wide (in KOH), 8-spored, with hemiamyloid apical ring (orange in IKI before treatment with KOH, blue after KOH), with croziers. Ascospores 0-1 septate, 11-18 x 3-4µm (in water), with lipid droplets.


I think my only reservation is that the paraphyses in water appear minutely granular, at least in the living state, but the contents more or less clear in KOH, apart from what looks like an occasional lipid droplet. Any words of wisdom will be gratefully received.


Best wishes
Nigel

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Hans-Otto Baral, 27-02-2021 20:19
Hans-Otto Baral
Re : Roseodiscus ?
Hi Nigel

clearly R. formosus in my opinion. In your pics I cannot seen the paraphysis contents, are you sure you saw the granules in living ones?

Zotto
DirkW, 27-02-2021 22:16
DirkW
Re : Roseodiscus ?
hi nigel, haven't  seen it for a long time. is it the first record in britain? did you recognise our paper on this species? its online. 

https://www.researchgate.net/publication/278728929_Roseodiscus_formosus_spec_nov_-_ein_bryophiler_Pionier_mit_falschem_Namen

best regards

dirk
Nigel Chadwick, 28-02-2021 09:38
Re : Roseodiscus ?
Hi Zotto and Dirk

Many thanks for your speedy responses. All images except the first are in KOH where the paraphyses were more or less clear. I struggled to photograph what I observed but I've attached a cropped section of the first image (in IKI) and part of another image (in water) where I tried to capture the granular appearance. I examined the specimen the day after I collected it.


Dirk - yes, of course. Without your paper I wouldn't have got very far. Roseodiscus isn't covered in 'Microfungi on Miscellaneous Substrates' which was my first attempt to find a name. When I began to search for info about Discinella I soon found your paper. My German isn't good very good so I pasted sections into Google Translate. It is also referenced in the following page which mentions at least one British record. This might be the second record.


http://fungi.myspecies.info/taxonomy/term/9140/descriptions


All the best
Nigel

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Hans-Otto Baral, 28-02-2021 09:51
Hans-Otto Baral
Re : Roseodiscus ?
It seems to me that these paraphyses are also dead, like the ascus which is surely dead.

I assume the first record listed there was that by Steven J. Heathcote in Messingham Heath, 21.II.2020. I have images in my folder which Carol Hobart forwarded to me, she made the micros, Steven the field photo. Regrettably the description there is not from this find but a copy of our paper.
Nigel Chadwick, 28-02-2021 10:22
Re : Roseodiscus ?
I see. I naively assumed that freshly mounted material would have living cells. Now I understand my mistake.

Thanks again for your help - hugely appreciated.
Nigel

Hans-Otto Baral, 28-02-2021 11:36
Hans-Otto Baral
Re : Roseodiscus ?
A frequent mistake. Of course, KOH kills cells, and also IKI, though tardily. But also pressure on the slide. best is trying sections because then it is easiest to avoid any pressure.