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04-11-2025 12:43

Edvin Johannesen Edvin Johannesen

Hi! One more found on old Populus tremula log in O

04-11-2025 09:07

Josep Torres Josep Torres

Hello.A suspected Hymenoscyphus sprouting on a thi

04-11-2025 14:53

Josep Torres Josep Torres

Hello.Very small, globose, mucronate perithecia, b

03-11-2025 21:34

Edvin Johannesen Edvin Johannesen

These tiny (0.4-0.5 mm diam.), whitish, short-stip

03-11-2025 19:41

David Chapados David Chapados

Hi,Does anyone knows which genus could this be? G

28-10-2025 15:37

Carl Farmer

I'd be grateful for any suggestions for this strik

03-11-2025 16:30

Hans-Otto Baral Hans-Otto Baral

Hello I want to ask you if you have found this ye

01-11-2025 09:14

Francis Maggi

Bonjour,Trouvé sur Xanthoria parietina à Valdebl

28-10-2025 19:33

Nicolas Suberbielle Nicolas Suberbielle

Bonjour à tous,Je voudrais votre avis sur cette r

31-10-2025 09:19

Lothar Krieglsteiner Lothar Krieglsteiner

Can somebody provide me with a file of:Rogerson CT

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Gnomonia gnomon?
Steve Clements, 13-04-2015 18:13
Hi,
this was found in the same place as the Orbilia, on the remains of a dead leaf by a stream. Oak, Sycamore and Hazel were present. The fruit bodies were on both sides of the leaf, and after soaking in water were up to 0.3 mm diameter. They were hardly immersed, rather attached by tiny "rhizoids", upo to 0.5 mmm long. The neck was between 0.25 and 0.35 long. What I assumed to be spores were in fact asci, containing very thin spores up to 25 x 1.5 um. I suspect this is Gnomonia gnomon, but my microscope is unable to show convincingly a central septum in the spores, nor appendages at the ends. Could this be anything else?
Many thanks if this find could be confirmed,
Steve
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Paul Cannon, 13-04-2015 18:34
Re : Gnomonia gnomon?
This could well be right, ascospore septa are quite difficult to see in these fungi. But most are host-specific, so it's important to know which plant the leaf comes from. There's a short description of the species at http://fungi.myspecies.info/taxonomy/term/5135/descriptions and a comprehensive monograph by Sogonov et al. (2008) in the CBS Studies in Mycology series (free to download)
Chris Yeates, 13-04-2015 19:17
Chris Yeates
Re : Gnomonia gnomon?
It certainly looks like a Corylus leaf to me

Chris
Steve Clements, 13-04-2015 20:36
Re : Gnomonia gnomon?
Yes - I recorded Stereum rugosum (and failed to find Hypoxylon fuscum) on the nearby Hazel, so I think that's very likely what it is. It doesn't seem to have been recorded in the Sheffield area (FRDBI records to 2009). My collection of over 80K records (Sheffield at centre of a 70 km square) gives
Gnomonia alni-viridis 7
Gnomonia cerastis 6
Gnomonia leptostyla 2
Most of these are on Acer.
(Most of these are also yours Chris)
Many thanks Chris and Paul
Alain GARDIENNET, 14-04-2015 07:49
Alain GARDIENNET
Re : Gnomonia gnomon?

Dear Steve,


As Paulm said, you'll have to go in Sogonov & al., and then in more recent works. The three taxa Gnomonia alni-viridis Gnomonia cerastis  Gnomonia leptostyla aren't used yet today.


Alain

Steve Clements, 14-04-2015 09:33
Re : Gnomonia gnomon?
Thank you Alain,
It's hard to know what to do with all the "old" records - we don't really know what many of them would be named as nowadays.
Les petits champignons! Les noms, ils se change si vite!
Steve
Stoykov Dimitar, 22-04-2015 16:01
Stoykov Dimitar
Re : Gnomonia gnomon?
Hi,

the leaf looks like of type of a hazel. Ascus's morphology (apical annulus is ca 1 micrometre), 27-31 x 4.6-6 micrones, spore 20 x 1.5 micr fits well in the description of Monod (1983: 85).
Important: Check the perithecia, if they collapse circular when the leaf is in dry condition, typical depression is noted by also by the author.


Steve Clements, 23-04-2015 21:03
Re : Gnomonia gnomon?
Hello Dimitar,
I have just checked my herbariun specimen - it has the circular depressions as you describe,
Kind regards,
Steve
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