|
Rosellinia franciscae L. E. Petrini.
Stromata uniperitheciate, scattered, dark brown to black, coated
with a thin light brown layer of subicular hyphae, globose with an obtusely conical
apex, 0.6-0.8 mm diam; subiculum present
during stromatal maturation, pale brown, felty, progressively disappearing.
Ostioles conical, papillate.
Asci cylindrical, with apical apparatus cuboid to rectangular
with an apical rim and a somewhat flared base, amyloid, 4-7.5 µm high x 4-4.5 µm broad.
Ascospores 27-35 x 6.5-7 µm, narrowly ellipsoid-inequilateral
with acute ends, pale
brown to brown, with a sigmoid and oblique germ slit about half spore-length on the less convex side;
appendages or slimy sheath absent.
Anamorph in nature: not seen.
Specimens examined: FRANCE: Pyrénées Atlantiques (64):
Auterrive, Ile du Gave d'Oloron, 17 Jan. 2000, FC-5384-3A, leg. Jean Vivant,
on Rubus;
Sauveterre de Béarn, 16 Apr. 1993, JFM-9346, on Phyllostachys.
Notes: Owing to its stromata nearly devoid of
subiculum when mature, R. franciscae is placed in subgenus Calomastia.
It is readily distinguished from other members of this group by its pale brown
ascospores provided with a short sigmoid and oblique germ slit. Except R.
evansii in which the germ slit is spiralling but spore-length,this feature
is unique among European taxa in Rosellinia, but is less uncommon in
the genus Xylaria (also compare to "Rosellinia" callosa).
It was first collected repeatedly on bamboo (Petrini,
1993), but a more recent collection on Rubus indicates that this host-preference
is not exclusive. Rosellinia franciscae is so far known only from Pyrénées
Atlantiques.
|
