05-03-2026 10:07
Hulda Caroline HolteHello, I found and collected this species growing
06-03-2026 09:41
Alain GARDIENNET
Hi forum, I'm now looking for another reference c
05-03-2026 16:30
François BartholomeeusenDear forum members, On the 2nd of February 2026,
19-02-2026 17:49
Salvador Emilio JoseHola buenas tardes!! Necesito ayuda para la ident
03-03-2026 20:34
Miguel Ángel Ribes
Good eveningThese small, amphora-shaped perithecia
01-03-2026 18:02
Francois Guay
I found this mystery Helotiales on an incubated le
Hi to allThis fungus forms subcuticular pseudothecia (¿?) under the periderm of stems of Arundo donax. These pulvinate and ostiolate ascomata, arranged in longitudinal lines, are singly or situated on small stromata with some other ones, 0.4-1.5 mm long, up to 0.15 mm high.
The 8-spored asci are cylindrical and I think they are bitunicate altough I can see maybe a small structure near the apex. The golden brown bi-cellular ascospores and the pseudoparaphyses are showed in the pics. I tough could be a Didymella or a close related genus, but I don't know a good genus for this collection.
Have you some ides for it?
Thanks again
not sure but your fungus looks like a Roussoella. If so the spores should be delicately longitudinally ribbed, it's difficult to see if the preparation is not very thin.
The smaller spores with broadly rounded ends would fit R. donacicola (Speg.) Ju, Rogers & Huhndorf which is common on this host. The slightly larger and more narrowly elliipsoid are less typical of this species and recall a tropical species, R. chiangraina (in Phytotaxa 181(1), 2014).
Saludos,
Jacques
Hi Jacques
Fantastic! I feel you are right, although the faint striate ornamentation is hardly visible. But the rest of the generic characters fits well with this fungus.
Thanks a lot!