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03-02-2026 20:44

Zetti Mario

When I first saw this white mould on an Agaricus s

18-08-2025 15:07

Lothar Krieglsteiner Lothar Krieglsteiner

.. 20.7.25, in subarctic habital. The liverwort i

02-02-2026 21:46

Margot en Geert Vullings

On a barkless poplar branch, we found hairy discs

02-02-2026 14:55

Andgelo Mombert Andgelo Mombert

Bonjour,Sur thalle de Lobaria pulmonaria.Conidiome

02-02-2026 14:33

Andgelo Mombert Andgelo Mombert

Bonjour,Sur le thalle de Peltigera praetextata, ne

31-01-2026 10:22

Michel Hairaud Michel Hairaud

Bonjour, Cette hypocreale parasite en nombre les

02-02-2026 09:29

Bernard CLESSE Bernard CLESSE

Bonjour à toutes et tous,Pour cette récolte de 2

01-02-2026 19:29

Nicolas Suberbielle Nicolas Suberbielle

Bonjour, Marie-Rose D'Angelo (Société Mycologiq

30-01-2026 22:49

éric ROMERO éric ROMERO

Bonjour tous, Récolté dans les Vosges le 22/10/

31-01-2026 09:17

Marc Detollenaere Marc Detollenaere

Dear Forum,On decorticated wood of Castanea,I foun

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Microscopic ascomycete.
Josep Torres, 24-09-2025 09:22
Josep TorresHello.
Very tiny apothecia, sprouting in a scattered manner, located on the surface of a semi-submerged trunk of Fraxinus sp.
Measuring only 0.07 to 0.11 mm in diameter, they are whitish in color and have a slightly hairy outer edge.
Marginal hairs with moderately pointed ends and inlaid surfaces.
The medullary exciple hyphae are intricate, and below these, hyphae are already tending toward globose angularis.
Octosporic asci, apparently without uncinules at their bases, mostly biseriate, and measuring (35.7) 40.9 - 52 (52.4) × (7) 7.7 - 9.1 (9.6) µm.
I can't provide data on the behavior of the asci to the Melzer test because I only managed to prepare a single sample with a single apothecium. The next day, the remaining apothecia had literally disappeared after dehydration.
Ellipsoidal ascospores with two large lipid droplets at the poles, with measurements of mature ascospores within the ascus of:
(5.9) 6.6 - 8.9 (9.3) × (2.9) 3.2 - 4.3 (4.7) µm
Q = (1.5) 1.8 - 2.4 (2.8) ; N = 30
Me = 7.6 × 3.6 µm; Qe = 2.1
The paraphyses are filiform, slightly or not at all widened at the apex, not protruding above the level of the asci, with one or two septa and a width of 2 to 2.55 microns.
Considering their characteristics, I think they are likely a Hyaloscypha, and among them is a Hyaloscypha microscopica, which, although the name would be appropriate, I have been unable to find any information about the species.
Any feedback from you would be most welcome.
Thank you in advance.
Best regards.
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Hans-Otto Baral, 24-09-2025 10:17
Hans-Otto Baral
Re : Microscopic ascomycete.
Will be difficult without the iodine reaction. Perhaps Hyaloscypha intacta which has inamyloid asci (in Lugol).

H. microscopica was not ever redescribed. SVrcek 1985 only combined it in Discocistella and Huhtinen 1990 did not study the sparse material.

I did not look up Velenovsky but assume that the hairs are not tapering.
Josep Torres, 24-09-2025 14:20
Josep Torres
Re : Microscopic ascomycete.
Thanks, Zotto.
Considering its tiny size, Hyaloscypha intacta seems like a good option. This has been mentioned here before. Here's a link to a study very similar to my proposal, which you yourself considered Hyaloscypha intacta.
http://ascofrance.com/forum/16979/hyaloscypha-hyalina#
Best regards.