Pleosporales - CBS - KNAW

Fungal Diversity
pseudoparaphyses (Fig. 61c). Hamathecium of dense, narrow
cellular pseudoparaphyses, 2–4.5 μm broad, septate (Fig. 61f).
Asci 153–170(−200)×17.5–21.5 μm (including pedicel),
bitunicate, fissitunicate, cylindro-clavate to clavate, pedicel
28–60(−85) μm long, 8-spored, biseriate, with an ocular
chamber best seen in immature ascus (to 3 μm wide×3 μm
high) (Fig. 61d and e). Ascospores 24–29×9–11 μm, oblong to
narrowly oblong, straight or somewhat curved, reddish brown
to dark yellowish brown, verruculose, with five transverse
septa and one vertical septum in each middle cells, constricted
at the primary and secondary primary septa (Fig. 61g).
Anamorph: none reported.
Material examined: PORTUGAL, Coimbra Lusitania,
on leaves of Fourcroya longava pr., Feb., 1881, leg. Moller.
(M 1183, holotype).
Notes
Morphology
Montagnula was introduced to accommodate two Pleospora
species, i.e. P. infernalis (Niessl) Wehm. and P.
gigantea Mont. by Berlese (1896), based on the presence of
hyphal stromatic tissues over the ascomata and asci with
relatively long pedicels (Barr 2001). Montagnula infernalis
was selected as the lectotype species (Clements and Shear
1931). Subsequently, Wehmeyer (1957, 1961) treated Montagnula
as a subgenus of Pleospora. Crivelli(1983) accepted
Montagnula as a separate genus, and divided it into two
subgenera, i.e. Montagnula and Rubiginospora. Montagnula
was characterized by having dark brown ascospores and
exclusively occurring on Agavaceae, while Rubiginospora
has reddish brown ascospores and occurs on Poaceae. This
proposal was not accepted by many workers (Barr 2001).
Subsequently, more species with various ascospores (such as
phragmosporous species by Leuchtmann (1984) and didymosporous
species by Aptroot (1995) were added in this
genus), which has obviously become heterogenic. Barr
(2001) assigned species of Montagnula into different genera,
i.e. Kalmusia and Didymosphaerella, respectively and introduced
Montagnulaceae to accommodate all of these genera.
Phylogenetic study
Montagnula opulenta forms a robust phylogenetic clade
with species of Bimuria, Curreya, Didymocrea, Letendraea,
Paraphaeosphaeria, Phaeodothis and Karstenula,
which might represent a familial group (Schoch et al. 2006;
Zhang et al. 2009a). A more convincing conclusion can
only be obtained following sequence data from more
verified fungi being added to the phylogenetic tree.
Concluding remarks
One striking character of Montagnula infernalis is the very
long ascal pedicel once it is released from the ascomata.
However, this character appears to have evolved more than
once and can be found in Kirschsteiniothelia elaterascus
Shearer which clusters with Helicascus (Shearer et al. 2009).
The same ascus character is also found in Xenolophium and
Ostropella in the Platystomaceae (Mugambi and Huhndorf
2009b). Montagnula opulenta is a didymosporous species,
but phylogenetically closely related to those dictyosporous
(Karstenula rhodostoma) and phragmosporous (Paraphaeosphaeria
michotii) members of Montagnulaceae (Zhang et al.
2009a). This might indicate that compared to other morphological
characters, ascospore type is not a valid character at
family level classification.
Moristroma A.I. Romero & Samuels, Sydowia 43: 246
(1991). (Pleosporales, genera incertae sedis)
Generic description
Habitat terrestrial, saprobic. Ascomata medium-sized, solitary,
scattered, or in small groups, superficial, cushion-like, circular
in outline, wall black, roughened, containing numerous
locules. Peridium thin, 1-layered. Hamathecium of dense, long
filliform pseudoparaphyses, 2–3 μm broad, septate, branching.
Asci polysporous, with a short, laterally displaced, sometimes
papillate knob-shaped pedicel, apex very thick walled,
bitunicate, fissitunicate, obclavate, ocular chamber not observed.
Polyspores oblong to cylindrical, hyaline, non-septate.
Anamorphs reported for genus: none.
Literature: Eriksson 2006; Romero and Samuels 1991.
Type species
Moristroma polysporum A.I. Romero & Samuels, Sydowia
43: 246 (1991). (Fig. 62)
Ascomata 100–210 μm high×340–600 μm diam., solitary,
scattered, or in small groups of 2–3, superficial, with basal
wall remaining immersed in host tissue, cushion-like,
circular in outline, wall black, roughened, containing
numerous locules, each locule 120–240 μm diam., ostiolate
(Fig. 62a and b). Peridium 14–30 μm thick, 1-layered,
composed of small heavily pigmented thick-walled cells of
textura angularis, cells2–4 μm diam., cell wall 1.5–3 μm
thick, peridium between the locules hyaline (Fig. 62b and c).
Hamathecium of dense, long filliform pseudoparaphyses, 2–
3 μm broad, septate, branching. Asci 44–60×12–14 μm
(x ¼ 54:3 13mm, n=10), polysporous, with a short, papillate
knob-shaped pedicel, apex very thick-walled, bitunicate,
fissitunicate, obclavate, ocular chamber not observed
(Fig. 62d and e). Polyspores 3–4(−5)×0.6–1.2 μm, oblong
to cylindrical, hyaline, non-septate, smooth (Fig. 62f).
Anamorph: none reported.
Material examined: ARGENTINA, Buenos Aires,
Ramallo, on Eucalyptus viminalis Labill., May 1982, Romero