Rosellinia diathrausta (Rehm) L. E. Petrini
Rosellinia diathrausta is another member of the subgenus Corrugata
with typical thin-walled stromata that are folded in the lower part and
seated on a felty subiculum. It deviates from other related species in that
its subiculum is white and soon disappearing (Petrini, 1993).
Ascospores of R. diathrausta resemble those of R. mycophila
in having one or two inconspicuous blunt cellular appendages and a conspicuous
slimy sheath surrounding the whole spore; they differ in being longer and much
broader [21.5-28.5 x 9.5-12.5 µm according to Petrini (1993), 22-27 x 7-10 µm
according to Francis (1986)] and in having a spore-length germ slit.
The main feature of R. diathrausta definitely is its peculiar ecological
requirements. According to Petrini (1993), it is restricted to dead branches
of conifers still attached to the trunk, in extreme environmental conditions
above 2000 m a. s. l.
Rosellinia diathrausta is known from Europe (Alps), Japan and North
America (Rocky Mountains) (Petrini, 1993), but was not yet collected in Pyrénées.