Fungi with septate hyphae and a dikaryophase

5. F\ngt wtth septale haphae a nd a dtkargophase
3. Pseudoparaphyses are hyphae found in some
bitunicate Ascomycota that originate from above the
asci and grow down between the developing asci and
become attached to the base of the ascal cavity.
They often become free from the upper part.
Pseudoparaphyses are often regularly septate, show
regular anastomosis and are often broader than
paraphyses, e.g. Pleospora spp.
4. Paraphysoids resemble pseudoparaphyses but
usually have fewer septa and are narrower;
anastomosis common, e.g. Patellaria spp.
5. Perlphysoids are short hyphae similar to
pseudoparaphyses but which do not reach the base
of the ascal cavity, e.g. Nectna spp.
6. Periphyses are hyphae that form a -fringe on the
inside of the ostiole or pore of ascomata and grow
towards the opening. They are septate, unbranched
and do not anastomose, e.g. Gibberella spp.
7. Hamathecial tissue absent (not figured), e.g.
Dothidea spp.
63
3. @@
The traditional system of classi$ring the Ascomycota is based on the tytrle of
ascoma, the structure of the ascus wall, the method of ascus dehiscence and the
method of development of the centrum (the structures within the ascoma such as
the asci and inter-ascal tissue). This system, which is now recognised as being
artificial because it does not indicate natural phylogenetic relationships, is
outlined inTable 5.1.
Table 5.1 Key to the classes of Ascomycota.
A" Asci unitunicate or if bitunicate then in the exposed h5rmenium of an apothecium.
B. Asci naked, formed as discrete free cells or in a hymenium of indefinite extent
but not bounded bv a stroma or bv ascoma tissue: asci indehiscent.
Class Hemiascomycetes
B.* Asci formed in ascomata
C. Asci scattered at various levels within a cleistothecium or a beaked
perittrecium; asci indehiscent.
Class Plectomycetes
C.* Asci formed at a common level in a hymenial layer or in a fascicle (a
group) at the base of the ascoma.
D. Ascoma usually a perithecium, less often a cleistothecium with
basal fasciculate asci or an ascostroma with unitunicate asci: asci
inoperculate, with an apical pore or slit.
Class P5zrenomycetes
D.* Ascoma an apothecium; asci operculate, inoperculate or
indehiscent.
Class Discomycetes
Ar' Asci bitunicate and formed in an ascostroma but not in an apothecium.
Class Loculoascomycetes
5.
6.