Message - 7th IAL Symposium

The 7 th International Association for Lichenology Symposium 2012
(4I-O3) Submission ID: IAL0069-00002
THE GENUS STAUROTHELE IN VIETNAM: SPECIES DIVERSITY AND
PHYLOGENETIC PLACEMENT
Gueidan C. 1
1 Botany, Natural History museum, London, United Kingdom
The Verrucariaceae is a mostly lichenized family comprising a large number of crustose saxicolous
species (e.g., Verrucaria, Staurothele, Polyblastia, Thelidium). These crustose species are especially diverse on
calcareous substrates, where they often are one of the main elements of the lichen flora. They are particularly
diverse in the Mediterranean-type and the temperate to cold temperate climates. In the wet Tropics, they are
only poorly studied so that their diversity and distribution is virtually unknown. A fieldtrip organized by the Natural
History Museum in London and the Vietnam National Museum of Nature in Hanoi allowed the author to collect
and study some specimens of crustose epilithic Staurothele from diverse localities in Northern Vietnam. The
morphological study of these specimens suggests that they belong to four different species, but none of them
seem to have been reported and treated in recent works on Staurothele. Molecular data (based on nuITS and
nuLSU) show that none of these specimens are in fact Staurothele, but they all belong to the mostly squamulose
genus Endocarpon. They form four to seven lineages of almost identical sequences, and are closely related to
Endocarpon diffractellum, a species of Staurothele recently transferred to the genus Endocarpon based on molecular
data. This study confirms that it is not possible to use the thallus structure as a character to differentiate
the two Verrucariaceae genera with hymenial algae, Endocarpon and Staurothele.
(4I-O4) Submission ID: IAL0088-00002
THE REPRODUCTIVE ECOLOGY OF ICMADOPHILA SPLACHNIRIMA –
A RARE AUSTRALASIAN LICHEN EXHIBITING SEXUAL AND ASEXUAL REPRODUCTION
Ludwig L. R. 1 , Lord J. M. 1 , Burritt D. J. 1 , Summerfield T. C. 1
1 Department of Botany, University of Otago, Dunedin, Otago, New Zealand
Icmadophila splachnirima grows preferentially in subalpine bogs and swamps of New Zealand (South
Isl., Stewart Isl., subantarctic Islands) and South-East Australia (Tasmania, Victoria). During a summer survey
of the distribution of this rare species, asexual reproduction was identified for the first time. This presentation
provides results from the first year of a PhD study into the reasons for and implications of a switch from sexual
to asexual reproduction in Icmadophila splachnirima. Preliminary results indicate that in more exposed microhabitats,
apothecial growth is reversibly arrested at an early developmental stage, always accompanied by
the formation of marginal soralia. This suggests an environmentally triggered switch from sexual to asexual
reproduction, possibly in response to adverse growth conditions, e.g. high-light and/or desiccation stress. This
hypothesis shall be tested experimentally during the remainder of the PhD study, and the presentation will give
an outline of the intended methods to achieve this, alongside with further preliminary results. A wide range of
aspects relating to the species’ biology and ecology will be part of this proposed work, including phytogeography,
phytosociology, micro-habitat conditions, physiology, anatomy, morphology and population genetics.
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