28-10-2025 15:37
Carl FarmerI'd be grateful for any suggestions for this strik
28-10-2025 11:29
Tanja Böhning
Hello, I found this very small (ca 0,5mm) yellow
27-10-2025 00:34
Francois Guay
I found this strange species in Québec,Canada, gr
27-10-2025 15:29
Michel Hairaud
Bonjour à tous, Avec Elisabeth Stöckli nous avo
26-10-2025 13:39
Joaquin MartinHi,I found this fungus in a mixed forest of spruce
26-10-2025 21:23
Juuso ÄikäsHello, a couple weeks ago I found some pale, whit
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!