20-12-2025 23:08
Patrice TANCHAUDBonsoir, récolte sur sol sablonneux dans l'arriÃ
21-12-2025 09:32
Josep Torres
Hello.A tiny ascomycete found embedded in wood in
20-12-2025 15:47
Mirek GrycHi.These grew on pine wood that was heavily covere
18-12-2025 21:17
Pol DebaenstThe identification took me to Byssonectria deformi
15-12-2025 07:09
Danny Newman
indet. Rutstroemiaceae sp. on unk. fallen leavesMc
19-12-2025 10:10
Patrice TANCHAUDBonjour, récolte réalisée en milieu dunaire, a
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Bruno Coué
Bonjour,je serais heureux d'avoir votre avis sur c
Black discs on Alder (Alnus) catkins
Edvin Johannesen,
29-10-2020 13:18
These black discs were growing along with Calycellina alniella on Alnus catkins. They are rather old and weathered, so cannot find structures other than spores (ascospores or conidia?), which are brown, mostly 3-septate, but up to 5-septate, 20-30 x 7-8 microns, and prismatic/sphaerical cells in the ascomatal wall. Difficult to see if the ascomata are erumpent or superficial, but they appear to be superficial.Â
Suggestions would be appeciated. Thanks!
Edvin
Hans-Otto Baral,
29-10-2020 14:52
Re : Black discs on Alder (Alnus) catkins
Did you see any asci? Perhaps try in KOH. Important is also a possible iodine reaction.
Edvin Johannesen,
29-10-2020 15:05
Re : Black discs on Alder (Alnus) catkins
I tried twice to find asci, but i seems like most of, if not all, the hymenium has disappeared. Not much material, but I will try once more. Thanks.
Martin Bemmann,
29-10-2020 15:22
Re : Black discs on Alder (Alnus) catkins
you will not find asci. This to my oppinion is the coelomycete Phragmotrichum rivoclarinum.
It is known from Alder and its catkins. (Sutton 1980: 36-37)
Regards
Martin
Edvin Johannesen,
29-10-2020 15:31
Re : Black discs on Alder (Alnus) catkins
That's great - I suspected it might be a coelomycete, but I didn't know there was a Phragmotrichum occuring on alder catkins. I do not have access til Suttons paper(s). Are you able to provide the 1980 paper, Martin?
Edvin Johannesen,
29-10-2020 15:34
Re : Black discs on Alder (Alnus) catkins
I find only two records worldwide (UK) of Phragmotrichum rivoclarinum in GBIF, which should incorporate all public databases in the world. Is it really that rare?
Martin Bemmann,
29-10-2020 15:36
Re : Black discs on Alder (Alnus) catkins
It is not a paper, but a book: B.C. Sutton, The Coelomycetes, Fungi Imperfecti with Pycnidia, Acervuli and Stromata, Kew 1980.
Here are the pages:
Edvin Johannesen,
29-10-2020 15:39
Re : Black discs on Alder (Alnus) catkins
Fantastic! I consider the case closed. (Must get that book :-)
Thanks a lot!
Hans-Otto Baral,
29-10-2020 15:59
Re : Black discs on Alder (Alnus) catkins
Great Martin! Now I also see the truncate base of the conidia in Edvin's first photo - quite impossible for ascospores.
Edvin Johannesen,
29-10-2020 16:13
Re : Black discs on Alder (Alnus) catkins
I also missed that truncate base, Zotto.
Martin Bemmann,
29-10-2020 18:09
Re : Black discs on Alder (Alnus) catkins
It was my hint to check for an coelo... ;-)
Edvin Johannesen,
29-10-2020 18:18
Re : Black discs on Alder (Alnus) catkins
And I just received the book :-)