20-05-2026 17:47
Margot en Geert VullingsWe found this Mollisia on dead Juncus stems mown l
20-05-2026 12:57
Ingo Ibelshäuser
Hello everybody, on decayed hardwood e.g. Quercus
22-04-2026 20:54
Enrique Rubio
Hi to everybody.This Pyrenopeziza grew in moist le
19-05-2026 12:55
Hardware Tony
After checking Gminder and Otto's library I cannot
19-05-2026 10:27
Patrice TANCHAUDBonjour, récolte récente sur terre retournée i
18-05-2026 12:43
Sylvie Le GoffBonjour à tousPuis je avoir votre aide sur ce que
19-05-2026 14:56
Åge OterhalsI found this white cushion-formed ascomycete on ro
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!