Octospora alpestris
Anamorph: not known.
Teleomorph: ascomata apothecia, 2-5 (-8) mm diam. and 2-3 (-8) mm tall, cupulate, short- to long-stalked, the disc bright orange, the margin sometimes paler and denticulate. Excipulum composed of thin-walled epidermoid cells to 15 µm diam., with an outer coating of hyaline thick-walled rhizoid-like hyphae in the lower part. Interascal tissue composed of unbranched paraphyses 3-4 µm diam., the apices curved but not noticeably swollen, containing orange carotenoid pigments. Asci 120-140 x 8-10 µm, cylindrical, with a long tapering stalk, thin-walled, the apex rounded to truncate, operculate, not staining in iodine, initially 8-spored but with the four lower spores usually aborting. Ascospores arranged uniseriately, 13-15 (-17) x 8-10 µm, ellipsoidal, aseptate, thin-walled, hyaline, with 1-2 large guttules, with an inconspicuous warted ornamentation.
Not formally assessed. The species appears to be rare, but could well be under-reported.
Distinguished by its moss host, and also by the usually four-spored asci and minutely verrucose ascospores.
Symbiotic with (or a biotrophic parasite of) the moss Tetraplodon mnioides.
Confirmed records only from VC77 Lanarkshire, VC103 Mid Ebudes (Mull) and VC104 N Ebudes (Skye). Reports on Barbula and an unknown moss from Hereforshire are probably misidentified.