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09-01-2026 17:41

Arnold Büschlen

Hallo, F. dilatata wird von vielen Bryoparasiten

10-01-2026 20:00

Tom Schrier

Hi all,We found picnidia on Protoparmeliopsis mur

07-01-2026 22:22

Danny Newman Danny Newman

Tatraea sp. on indet. hardwood The Swag, Great Sm

10-01-2026 01:18

Danny Newman Danny Newman

cf. Neovaginatispora fuckelii on indet. shrub Pre

07-01-2026 10:24

Danny Newman Danny Newman

Pezicula sp. on indet. hardwood Appalachian Highl

09-01-2026 10:08

Blasco Rafael Blasco Rafael

Hola, en el mismo habitat que la anteriorRetamaDia

08-01-2026 21:22

Blasco Rafael Blasco Rafael

Hola, He recogido esta muestra de Orbilia sobre Re

07-01-2026 17:29

Marc Detollenaere Marc Detollenaere

Dear Forum,On a barkless Populus I found some smal

10-11-2021 17:33

Riet van Oosten Riet van Oosten

Add-on topic http://www.ascofrance.com/forum/7059

07-01-2026 10:05

Danny Newman Danny Newman

cf. Chaetospermum on XylariaCosby Campground, Grea

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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."