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ABSTRACT 4
ABSTRACT
A taxonomic revision of the Australian members of trentepohlioid, ecolumellate
thelotremataceaen Graphidaceae (Ostropales, lichenized Ascomycota) is presented. This
species-rich group of crustose, predominantly tropical and subtropical lichens has been
neglected for a long time, and is still poorly known. Particularly the studies for Australia are
highly fragmentary.
Approximately 4000 specimens, including a total of c. 500 type specimens, herbaria
collections, and almost 1000 samples collected during two field trips, were examined
morphologically, anatomically, and chemically. A total of 103 species of 13 genera (including
one newly described genus) could be identified. 33 species are new records for Australia, and
20 species were described new to science. Of the currently listed 71 names of this group for
Australia, 50 are accepted as valid species. The remaining names and species, listed in an
appendix, proved to belong to other genera, be synonymous to other taxa or falsely identified
collections. 21 species (including species not known for Australia) are newly combined and
several new synonyms are proposed.
In the taxonomic part an introduction is provided, including a historical overview of the
development of generic concepts and delimitations within the treated group. This is followed
by a brief presentation of earlier taxonomic studies and collections of thelotrematoid lichens
in Australia. It also provides a general treatment of the climatic and biogeographical
conditions of the continent. Further, the main characters are described, including anatomical,
morphological and chemical features. The ecology and distribution of thelotrematoid lichens
are discussed. All treated species are described and illustrated, their distribution is mapped,
and a key for the identification provided. An overview of the distinguishing characters
between genera is presented in a table.
To illuminate the phylogenetic relationships within this group, three phylogentic analyses
were carried out using partial sequences of nuclear and mitochondrial ribosomal DNA loci.
The first analysis employed a combined dataset of the mitochondrial SSU (mtSSU) and the
nuclear LSU (nuLSU) of 105 species of Ascomycetes. As a result, it could be shown that the
hitherto separted two families of Ostropales, Graphidaceae and Thelotremataceae, are not
monophyletic, but form several lineages within one strongly supported monophyletic group.
Consequently, Thelotremataceae is reduced to synonymy with Graphidaceae. The second and
third analyses were carried out using a single dataset of nuLSU and mtSSU sequences
respectively. In the nuLSU analysis 40 specimens of 38 species were included, in the mtSSU
analysis 50 specimens of 25 species were examined. These analyses showed that all genera of
thelotrematoid lichens included in the study are para- or polyphyletic, with the sole exception
of Diploschistes, and that the present generic concept within Graphidaceae needs revision.
The new genus Melanotopelia is introduced based on molecular and morphological evidence.