Biscogniauxia granmoi Lar. N. Vassiljeva
Stromata applanate, discoid, 7-10 mm diam x 2-2.5 mm thick, with slightly
raised margins; surface blackish, carbonaceous; the tissue beneath the perithecia
greyish, up to 1.5 mm thick, extending into the substrate, limited by a black
Perithecia narrowly ovoid to tubular, 0.4-0.5 mm
diam x 0.8 mm high.
Ostioles umbilicate, inconspicuous, in our specimen
hidden under black ascospores masses.
Asci short-stipitate, with a discoid
amyloid apical ring.
Ascospores medium brown, ellipsoid slightly inequilateral
with broadly rounded ends, 11.5-13.5 x 6-6.8 µm, with straight, conspicuous
germ slit spore-length on the less convex side.
Specimen examined: AUSTRIA: Niderösterreich, Korneburg district, Rußbach,
500 m S of Dauersberg, 300 m alt, 7562/1, 01 May 1996, on Prunus padus,
leg. A. Hausknecht.
Notes: The above description is based on material kindly sent to FC
by Dr. A. Granmo. For a more comprehensive description, the reader is refered
to Læssøe et al. (1999).
Biscogniauxia granmoi is morphologically similar to the
widespread B. nummularia, from which it differs primarily in having umbilicate
ostioles, tubular perithecia, paler and more slender ascospores, and in being
restricted to Prunus padus in northern Europe. It is so far known from
Austria, Latvia, Norway, Poland and Far Eastern Russia (Læssøe et al.,1999),
and is not yet reported from France.