20-04-2026 22:00
Malcolm Greaves
These pale yellow, hairy ascos were growing on cul
19-04-2026 21:23
Steve ClementsBonjour, I found this anamorphic fungus on old pl
19-04-2026 20:46
Steve Clements1 mm diameter approx spherical conidiophores on pl
12-04-2026 17:56
Hardware Tony
Found on dead stems in February earlier this year
17-04-2026 19:16
Enrique Rubio
Hi to everybodyI would appreciate any assistance r
14-04-2026 05:32
Ethan CrensonHi all, A few weeks back a friend pointed out som
17-04-2026 15:14
Bruno Coué
Bonjour.Récoltes du 16/04/2026, sur feuilles mort
12-04-2026 15:52
Gernot FriebesHi,I'm looking for help with this anamorph collect
14-04-2026 21:52
Gernot FriebesHi,found on dead leaves of Carex elata. Conidia: 4
16-04-2026 22:09
Buckwheat PeteHello, I'd like to ask about this older specimen:
Hypoxylon submonticulosum ?
Ethan Crenson,
15-01-2020 22:42
Hello,
Last weekend in New York City I collected an effuse Hypoxylon on decorticated hardwood that had purple KOH-extractable pigments. I looked in Ju and Rogers and found that there are few North American Hypoxylon species that have that feature. I thought perhaps this could be Hypoxylon submonticulosum.
The surface pigment is dark brick red. The ostioles are higher than the stromatal layer. There are no colored granules just below the surface of the stroma. There is a small but visible layer of stroma below the perithecia.
Asci are 112-137 x 7.5-8.5µm with the spore bearing part 76-86µm. Apical ring is IKI+.
Spores measure 9-13 x 4-5µm, ellipsoid/inequalateral-ellipsoid with tapered ends, brown or light brown (it seems there were not a lot of mature spores, leading me to believe that this could be a young specimen). There are usually 2 to 3 oil droplets. It is very difficult to detect if there is a germ slit, but I think I saw one which is almost full spore length.
There is note in Ju and Rogers which indicates that for both H. monticulosum and H. submonticulosum there can be a purple KOH pigment reaction "only in the young stromata", otherwise there is none. I checked the reaction twice. At home under artificial light the reaction is less purple and more dark red/burgundy.
Does anyone, particularly Jacques Fournier (!) have any thoughts on this possible Hypoxylon submonticulosum?
Thanks in advance,
Ethan
Jacques Fournier,
16-01-2020 16:06
Re : Hypoxylon submonticulosum ?
Hi Ethan,
I agree with you, your fungus meets all the key features of H. submonticulosum. Just reaction of perispore to KOH is missing but it is difficult to assess in this species. The germ slit is also often more conspicuous in KOH.
For your information, this fungus was recently excluded from Hypoxylon and moved to the new genus Hypomontagnella (Lambert et al. 2018). I send you the paper privately.
All my best,
Jacques
Ethan Crenson,
16-01-2020 17:21
Re : Hypoxylon submonticulosum ?
Jacques,
Thank you for your help! I just prepared another slide and I was able to detect the reaction of the perispore in KOH and also saw clearer view of the germ slit. Now I can see that it is clearly less than spore length. Thank you also for the paper. My collection keyed rather nicely to Hypomontagnella submonticulosa.
Best regards,
Ethan
Jacques Fournier,
16-01-2020 18:37
Re : Hypoxylon submonticulosum ?
excellent observations! the germ slit is clearly shorter than the spore length, and the perispores are indeed dehiscing but thin-walled and smooth, making them easily overlooked.
Your collection conforms absolutely well to H. submonticulosa.
Cheers,
Jacques