27-11-2025 15:41
Thomas LæssøeSpores brownish, typically 4-celled; 26.8 x 2.4;
27-11-2025 12:01
Thomas Læssøehttps://svampe.databasen.org/observations/10496727
27-11-2025 11:46
Thomas Læssøehttps://svampe.databasen.org/observations/10493918
27-11-2025 11:31
Thomas LæssøeCollectors notes: Immersed ascomata, erumpent thro
23-09-2025 13:31
Thomas Læssøehttps://svampe.databasen.org/observations/10534623
25-11-2025 14:24
Thomas Læssøehttps://svampe.databasen.org/observations/10490522
26-11-2025 18:13
The entire run of Mycotaxon is now available throu
25-11-2025 11:03
Mick PeerdemanHi all,One of my earliest microscopy attempts, so
Hymenoscyphus sur feuille de Betula
Louis DENY,
28-09-2023 16:36
Tourbière de la Grande Pile. Haute Saône.
Blanc, diamètre 1 mm
Aques sans crochet, 100X10 µ
Spores non scutulloides (ou à peine): 14-16 X 5 µ. OCI = 5. Quelques gouttes moyennes et nombreuses petites aux extrémités
Paraphyses avec VB
Semble correspondre à H. caudatus, mais la forme des spores ainsi que leurs dimentions me semblent légèrement différentes.
En parcourant la clé de B. Declercq, j'arrive sur H. betulae, qui semble très voisin.
Merci de me faire part de votre avis
Hans-Otto Baral,
28-09-2023 17:37
Re : Hymenoscyphus sur feuille de Betula
Yes, I have some photos made by Bernard Clesse which look very much like yours and are identified as H. betulae.
In principle, your collection is H. sparsus, but that species I have mainly found on Quercus, rarely Fagus. But: one collection was on Betula (HB 866). In all these finds the lipid content of the spores is rather low, for which reason B. Declercq appears to have separated his species. Whether this is a good character I cannot tell.
Important is also that the VBs in the paraphyses are restricted to the upper 8-25 µm, with only scattered ones further down, in contrast to H. caudatus. And the contents are multiguttulate. This you can see on Boudier's plate. (see my folder sparsus).
In B. Clesse's H. betulae the VBs are more elongated and fill the entire width of the paraphysis, also they reach further down. Both is the case in your find as well.
Louis DENY,
28-09-2023 21:51
Re : Hymenoscyphus sur feuille de Betula
Merci Zotto.
Jean-Luc Ranger,
29-09-2023 08:57
Hans-Otto Baral,
29-09-2023 09:46
Re : Hymenoscyphus sur feuille de Betula
Hmm, this requires a photo of free spores in water to be sure, also spore size.
Hans-Otto Baral,
29-09-2023 12:09
Re : Hymenoscyphus sur feuille de Betula
Yes, this could fit, but one must be cautious, H. caudatus may occur with almost homopolar spores. The contents of the paraphyses seem to confirm your opinion.





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