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02-05-2025 13:29

Isabelle Charissou

Bonjour, j'aimerais savoir s'il y a eu des public

09-05-2025 16:01

Thomas Flammer

I found a black cushon which might eventually be 

06-05-2025 13:37

Thomas Flammer

Munk, Anders (1953). The System of the Pyrenomycet

08-05-2025 20:50

Andreas Jacob

Good evening, due to contstant drought I started

07-05-2025 18:29

Francois Guay Francois Guay

I found this small hyaline ascomycete on moist, de

08-05-2025 02:22

Francois Guay Francois Guay

I found this white, hairy ascomycete on the bark o

08-05-2025 18:32

Ethan Crenson

Hello all, I was looking at leaves of Yucca from

08-05-2025 08:59

Castillo Joseba Castillo Joseba

Me mandan el material de Galicia, (España) , reco

07-05-2025 10:18

Thomas Flammer

I have found on Genistae sth. that looks like puli

05-05-2025 09:35

Nicolas Suberbielle Nicolas Suberbielle

Bonjour à tous,Marie-Rose d'Angelo de la SociétÃ

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Melanomma?
Hans-Otto Baral, 20-08-2010 13:11
Hans-Otto BaralHi

In Middle-Sweden (Saxnäs) grew a bitunicate pyreno on Sorbus aucuparia standing branch together with Orbilia aristata etc. I compare ist with Melanomma but the spores are hyaline, apparently they are ejected when 1-septate, but get more septa when older, still remaining hyaline. Many perithecia are overmature but some are o.k.

Zotto
  • message #12527
Hans-Otto Baral, 20-08-2010 13:14
Hans-Otto Baral
Re:Melanomma?
1-septate Spores ca. 15-18 x 6-6.5 µm, overmature 17-23 x 7-8.5 µm
  • message #12528
Hans-Otto Baral, 20-08-2010 13:15
Hans-Otto Baral
Re:Melanomma?
The small tree was dead because of too much shade.
  • message #12529
Hans-Otto Baral, 23-08-2010 10:03
Hans-Otto Baral
Re:Melanomma?
Section of perithecium
  • message #12550
Hans-Otto Baral, 23-08-2010 10:04
Hans-Otto Baral
Re:Melanomma?
near ostiole
  • message #12551
Hans-Otto Baral, 23-08-2010 10:06
Hans-Otto Baral
Re:Melanomma?
perithecia attached by a short stipe
  • message #12552
Hans-Otto Baral, 07-09-2010 22:54
Hans-Otto Baral
Re:Melanomma?
I've sent my images to Walter Jaklitsch, and he has an idea:

"I collected this fungus several times on about 10 different, unrelated hosts including Spiraea. Some of my specimens were examined by Andre Aptroot, who determined them as Dothidotthia ramulicola (Peck) M.E. Barr. I think one of them was also confirmed by Barr as this fungus. I do not think that they were right, because Dothidotthia has broad, nearly ellipsoid asci with biseriate ascospores, while Otthia has cylindrical asci with uniseriate ascospores, similar to your specimen, where perhaps the spores are not strictly uniseriate.

Anyway, I think that your fungus is Otthia spiraeae (there may be several species hidden under this name ??), immature and aberrantly developed. It seems that ascospores develop very slowly in this species and that unfavourable conditions disturb their development, leaving them in a certain stage without chance of maturing. When mature, ascospores of Otthia spiraeae are about (17-)21-28 x 11-13(-15) µm, very dark brown, 2-celled, with or without various combinations of delicate secondary septa; the 2 cells may be grossly muriform; when hyaline they are 16-23(-25) x 7-9 µm and also develop quite strange combinations of septa, as you show in one of the images. I collected specimens with hyaline ascospores from December to April, so this kind of development may be correlated with low temperatures, or let´s say development is retarded or stopped by low temperatures (?).

Also the ascomata in your images are exactly what I have seen, often with a pallid or dark and stellate ostiolar area in the same specimen.

Interestingly, Barr descibed additional/secondary septa for D. ramulicola
and also ascospore size (of the hyaline spores) fits better. So, in absence
of an anamorph, and if the asci may not be so important, one could also
think of D. ramulicola."