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21-04-2026 22:14

Margot en Geert Vullings

This cup fungus was found on April 10, 2026, on lo

22-04-2026 20:17

Marian Jagers Marian Jagers

Is anyone familiar with the Hyphomycetes genus Pse

22-04-2026 20:54

Enrique Rubio Enrique Rubio

Hi to everybody.This Pyrenopeziza grew in moist le

22-04-2026 19:12

Louis DENY

Bonjour forum.Trouvé à Belfort, est de la France

21-04-2026 21:00

Sylvie Le Goff

Bonjour à tousJe sollicite votre aide pour cet as

22-04-2026 01:06

Richard VALERI Richard VALERI

Bonjour à tous.Je vous présente cette Nectria s.

21-04-2026 13:36

Gernot Friebes

Hi,I am out of ideas for this one. I collected Sal

21-04-2026 13:19

Gernot Friebes

Hi,this Lophodermium on Typha has ascospores measu

21-04-2026 13:05

Gernot Friebes

Hi,this hyphomycete feels familiar but I was not a

20-04-2026 22:00

Malcolm  Greaves Malcolm Greaves

These pale yellow, hairy ascos were growing on cul

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Phaeohelotium on deciduous wood?
Oskari Virtanen, 29-12-2025 09:38
Hi,
could anyone help me identify this, I suspect Phaeohelotium or maybe Hymenoscyphus? I was thinking something along the lines of Leptodontidium (/P.) trabinellum or P. fulvidulum but I couldn't get the asci or spore size to fit.

- On rotten, decorticated deciduous wood (Betula or Populus), damp mixed forest, Southwest Finland (Turku), December 2025.
- Diameter approx. 1.5 mm, growing gregariously in a 20 cm area, almost sessile.
- Asci 8-spored, IKI+, with croziers, (105.4) 115 - 124.8 (127.4) × (6.6) 6.8 - 7.7 (8.8) µm.
- Living spores in water (10.3) 10.6 - 13.8 (14.2) × (3.5) 3.8 - 4.6 (4.9) µm, Q = (2.3) 2.6 - 3.3 (3.4); N = 25, occasionally 1-septate.
- Paraphyses rarely exceeding asci, with some droplets, apices never swollen, 1.5 - 2.8 µm at the apex.


I'm quite new to asco microscopy so please let me know if you need anything else. :)


Best,
Oskari

  • message #84190
  • message #84190
  • message #84190
  • message #84190
  • message #84190
Hans-Otto Baral, 29-12-2025 09:46
Hans-Otto Baral
Re : Phaeohelotium on deciduous wood?
Ascus and spore size is not the only critical detail, but look at the apical ring of the Calycina type. Can you exclude Calycina citrina?
Nicolas VAN VOOREN, 29-12-2025 09:46
Nicolas VAN VOOREN
Re : Phaeohelotium on deciduous wood?
In my opinion, the amyloid reaction of asci is of Calycina-type, so this excludes Phaeohelotium or Hymenoscyphus...
Oskari Virtanen, 29-12-2025 09:58
Re : Phaeohelotium on deciduous wood?
The microscopy does indeed fit C. citrina, and looking at the descriptions I see no good reason to exclude it. I'm used to seeing it a much brighter yellow, so I mindlessly went past it. Also good to know that this type of reaction is common to Calycina. Thank you both!