05-02-2026 15:07
Vasileios Kaounas
Found on a fallen needle of Pinus halepensis, diam
05-02-2026 06:43
Stefan BlaserHello everybody, Any help on this one would be mu
18-08-2025 15:07
Lothar Krieglsteiner
.. 20.7.25, in subarctic habital. The liverwort i
02-02-2026 21:46
Margot en Geert VullingsOn a barkless poplar branch, we found hairy discs
02-02-2026 14:55
Andgelo Mombert
Bonjour,Sur thalle de Lobaria pulmonaria.Conidiome
02-02-2026 14:33
Andgelo Mombert
Bonjour,Sur le thalle de Peltigera praetextata, ne
31-01-2026 10:22
Michel Hairaud
Bonjour, Cette hypocreale parasite en nombre les
02-02-2026 09:29
Bernard CLESSE
Bonjour à toutes et tous,Pour cette récolte de 2
I found this stromatic fungus growing on the wood of _Castanea sativa_. The stroma is brown and exsudes a red pigment in KOH. The asci are very long
and thin, up to 150 x 6 µm, unitunicate, apically amyloid, and contain 8-spores each, uniserially arranged at the top. The spores are one-celled, hyaline when
young and soon brown, guttulate, with the following dimensions:
(6.7) 6.9 - 7.7 (8.1) × (3.3) 3.5 - 4.1 µm
Q = (1.8) 1.81 - 2.1 (2.2) ; N = 27
Me = 7.4 × 3.8 µm ; Qe = 1.9 ,
which are much smaller than my previous observations of similar fungi. Can someone help me in give it a name?
Thanks in advance,
zaca
it fits well Annulohypoxylon minutellum, formerly known as Hypoxylon cohaerens var. microsporum.
Jacques
The size of the spores troubled me.
Best wishes,
zaca
D'accord pour Annulohypoxylon minutellum mais le support m'intrigue. J'ai souvent récolté cette espèce mais toujours sur Quercus sp.
Amicalement
Paul
cheers
After the proposal of Jacques, I looked for more information about this species and in the description of Hypoxylon cohaerens at the webpage "Pyrenomycetes from southwestern France"
http://pyrenomycetes.free.fr/hypoxylon/html/Hypoxylon_cohaerens.htm
I found the following text that I quote:
"Notes: Hypoxylon cohaerens is a common saprophyte of beech forests, characterized by black pulvinate stromata constricted at base with papillate ostioles. Two other taxa, H. cohaerens var. microsporum and H. multiforme, share similar stromatal features, and field identification relies mainly on host identification: H. cohaerens is restricted to Fagus while H. cohaerens var. microsporum is restricted to Quercus and Castanea and H. multiforme grows mostly on Betula, Alnus and Corylus. However, one collection made on Ligustrum vulgare, a member of Oleaceae, [Hautes Pyrénées (65), Bagnères de Bigorre, L'Arbizon, 04 Sept. 2002, JF-02154, leg. FC] proves that host specificity is rarely absolute."
From it I infer that Castanea sativa is a common host for Annulohypoxylon minutellum (formerly known as Hypoxylon cohaerens var. microsporum, as Jacques mentioned). Am I wrong?
Best wishes,
zaca
Hi together,
what grows on Quercus also grows on Castanea. There is no fungus I know (mycorhizal or saprotrophic) growing with/on Quercus that does not grow with/on Castanea. Example: even the typical Castanea-fungus Rutstroemia echinophila can be found on Quercus leaves and cupules.
Regards from Lothar
Best wishes,
zaca