The old generic name Nemania S. F. Gray was
Pouzar (1985 a, 1985 b) in order to accommodate a group of
species related to Hypoxylon serpens ( Pers.: Fr.) J. Kickx fil. that
were previously classified by
in Hypoxylon Bull. section Papillata
subsection Primo-cinerea. This generic concept was later accepted
by other authors, for the cultural data presented by
Petrini and Rogers (1986)
and the narrower delimitation of Hypoxylon proposed by
Ju and Rogers (1996)
led to the necessity to segregate this group from Hypoxylon.
from Hypoxylon on the basis of the following characters, developed by
Granmo et al. (1999),
Laessøe et al. (2000) and
Ju and Rogers, (2002): in Nemania,
stromata are dark brown to black, one-layered, more or less carbonaceous and usually have,
at least at first stages of their development, a whitish soft tissue between
and/or beneath the perithecia; they lack coloured granules and do not yield
pigments in 10% KOH. Ostioles are typically papillate. Asci are provided with
an apical apparatus usually higher than broad or at least cuboid. Ascospores
are frequently pale brown, mostly with an inconspicuous germ slit which is
located on the less convex side, and lack a perispore dehiscing in 10%
KOH. Immature ascospores often bear a fugacious and inconspicuous cellular
appendage. Anamorphs are referable to Geniculosporium Chesters and
Greenhalg. In addition, young stromata growing under the anamorph usually keep
a loose hyphal cottony coating which is coloured in shades of white,
brown, ochreous grey, grey or greenish yellow and vanishes at maturity. Most of these
features show that affinities of Nemania rather lie with effused forms
of the heterogenous genus Xylaria than with Hypoxylon. Moreover,
D. N. A. sequencing of various xylariaceous taxa carried out by
al. (1999) supports the segregation of Nemania as a distint clade.
For synonymy of taxa treated further, the reader is referred to the above
authors (Granmo et al., 1999; Ju and Rogers, 2002).
A thorough and
systematic examination of all Nemania specimens collected during this
study showed that the stromatal morphology does not allow a reliable distinction
between most of European Nemania taxa, for intraspecific variations often
have a broader range than interspecific differences.
represents about 90% of the collected specimens in our area, and its stromatal
variations make its field identification nearly impossible, but fortunetaly
it is readily recognized microscopically owing to the dextrinoid reaction of
the ascal apical apparatus. In our experience,
N. confluens and
N. serpens var.
colliculosa are not uncommon, while other taxa occur
occasionally to very rarely.
In this study we present
five unnamed species which more or less deviate from the known Nemania
species. All of them might represent new taxa, but they are represented by too
scanty material. Additional records are expected in future, so that they can
be cultured and compared to known taxa.
are mostly found growing on decorticated rotten wood of Angiosperms.
Nemania diffusa and
N. aenea var.
aureolutea are distinctive in growing
likewise on bark, and interestingly
N. confluens and N. serpens were once recorded on
wood of Abies alba. As many other xylariceous fungi, Nemania species
have been isolated as endophytes
(L. Petrini and O. Petrini, 1985;
Ju and Rogers,
2002), but unlike in other genera, none of them is apparently host-specific.