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17-04-2021 15:01

Khomenko Igor Khomenko Igor

Hi, I'm having trouble identifying this hairy disc

17-04-2021 19:34

Juuso Äikäs

This Thursday I found some tiny discos growing on

16-04-2021 08:53

Pierre-Yves Julien

Bonjour à tous, 1er post pour moi sur ce forum.R

17-04-2021 13:41

Angel Pintos Angel Pintos

Hello everybody,Anyone on the forum is from Götti

16-04-2021 22:02

Bo Valeur Bo Valeur

Hi thereThis Nice Lachnum was found on a dead bran

17-04-2021 11:45

Karl Soler Kinnerbäck Karl Soler Kinnerbäck

Hi!Could this be a Nigrograna? I first thought it

09-04-2021 18:44

Mirek Gryc

Hi.Probably anamorph but I have never seen so big

17-04-2021 09:18

Savic Dragisa

Hello everyone,on a corn stalk. I have no idea wha

12-04-2021 19:35

Mirek Gryc

Hello everyone.I'm not sure if it was a branch of

15-04-2021 14:24

Castillo Joseba Castillo Joseba

Me mandan el material seco recolectado en el compo

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

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

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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?

DirkW, 27-02-2021 22:16
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.

best regards

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.

All the best

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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.

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.