Pleosporales - CBS - KNAW

Fungal Diversity
10–20 μm wide at sides, comprising one cell type of
2–3 layers of thick walled scleroparenchymatous cells,
cell wall 2–5 μm thick, peridium thicker near
the apex (Fig. 56b). Hamathecium of dense, trabeculate
pseudoparaphyses, 1–2 μm broad, septate, branching
and anastomosing. Asci 120–173×18–25 μm
(x ¼ 133:2 20:5mm, n=10), 8-spored, bitunicate, fissitunicate
dehiscence not observed, broadly cylindrical to
cylindro-clavate, with a short, thick, furcate pedicel, up to
15 μm long. Ascospores 32.5–42×10–13 μm
(x ¼ 36 11:2mm, n=10), narrowly ellipsoid, usually
slightly curved, dark brown, 7–9 septa, slightly constricted
at the median septum (Fig. 56c and d).
Anamorph: none reported.
Material examined: SWITZERLAND, Kt. Wallis,
Findelen, Artemisiae campestris L., 10 Sept. 1895, H.
Wegelin (ZT, holotype).
Notes
Morphology
Massariosphaeria was established by Müller (1950) as
a section of Leptosphaeria based on its large, thick-walled
ascospores with a mucilaginous sheath as well as its
ascomata with a thick apex. Massariosphaeria was
introduced as a separate genus by Crivelli (1983),
characterized by its wide peridial apex comprising
thick-walled cells, compressed to round papilla, and
relatively large, thick-walled, reddish brown to brown,
multi-septate to dictyosporous ascospores, usually surrounded
by a sheath (Crivelli 1983; Huhndorf et al. 1990;
Leuchtmann 1984). In particular, Crivelli (1983) emphasized
that species of Massariosphaeria often stain the woody
substrate (or culture) purple, and this was accepted by
Leuchtmann (1984). Barr (1989c) had treated Massarios-
Fig. 56 Massariosphaeria
phaeospora (ZT, holotype). a
Ascomata scattering on the host
surface. Note the immersed to
erumpent ascomata. b Section of
a partial peridium. Note the
peridium structure. c, d Released
ascospores. Scale bars:
a=1 mm, b–d=20 μm