Microscopic Photos: ascomata, asci and ascospores
Wettsteinina macrotheca (Rostrup) Muller
AC – 2491. on dead leaves of Carex sp., Lake Verde bog, 62.87 degW 46.245degN, July 5, 2021, PEI CANADA. (Deposited in NB Museum herbarium)
Ascomata small immersed with large ostiole, spores 48-58×13-15µm, spores have a thick irregular sheath when fresh, when dried and rehydrated sheath seems to loose shape but appears as a very thin outline; paraphyses seem to be present. Ascospore cytoplasm pulls back to form a distoseptate aspect (best seen in Lacto blue stain see photos below)
According to Mycoportal the species has been reported from Sweden, Norway, Denmark (Greenland) and Canada (Quebec and British Columbia). All collections are in northern parts of the territory or alpine conditions. The PEI collection is the first in southern latitudes near sea level, possibly the southern limit for the species.
Barr, 1972. Dothideales p.549 smaller spores.
Shoemaker & Babcock, 1986. Wettsteinina. CJB 65:373-405.