05-07-2025 12:38
Åge OterhalsI found this pyrenomycetous fungi in pine forest o
02-07-2025 18:45
Elisabeth StöckliBonsoir,Sur feuilles d'Osmunda regalis (Saulaie),
04-07-2025 20:12
Josep Torres
Hello.A fungus growing on the surface of a trunk o
20-06-2025 08:33
Josep Torres
Hello.Small, blackish, mucronated surface grains s
28-06-2025 16:00
Josep Torres
Hello.A tiny fungus shaped like globose black grai
04-07-2025 12:43
Castillo Joseba
me mandan el material seco de Galicia (España)
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!