2: Species on Lecanora s. l., Rhizoplaca and Squamarina

Abstract A study on the taxonomy, morphology and anatomy of the lichenicolous species of the genus Cercidospora (Dothideales, incertae sedis) growing on lichens of the genera Lecanora (Lecanoraceae), specifically of the L. polytropa group and the L. saxicola group (i.e. L. muralis sensu auct. group, Protoparmeliopsis spp.), Rhizoplaca (Lecanoraceae) and Squamarina (Stereocaulaceae) is presented. The following species are proposed as new: Cercidospora barrenoana on Rhizoplaca peltata, and C. melanophthalmae on Rhizoplaca melanophthalma. C. stenotropae is proposed provisionally; this fungus grows on Lecanora stenotropa and other taxa of the L. polytropa group. A key for the species of the genus Cercidospora treated is provided

Iron localization in Acarospora colonizing schist on Signy Island

A small, inconspicuous lichen, Acarospora cf. badiofusca, was discovered colonizing ironstained quartz mica schists on the lower slope of Manhaul Rock, a recently exposed nunatak on the McLeod Glacier, Signy Island, South Orkney Islands. Thallus colour ranged from rust on exposed rock surfaces to paler orange and green in shaded crevices. This study addressed the hypothesis that colour reflects element localization, and considered substance localization within lichen tissues and responses to stress. Electron microprobe analysis of specimens confirmed that Fe is localized principally in the outer rust-coloured part of the cortex, confirming that the colour reflects Fe localization. Oxalates, widely reported as contributing to tolerance mechanisms to environmental stress, were not detected using X-ray diffraction. The upper thallus surface consisted of sub-micron particulate phases containing Fe, Al and O, suggesting mixed oxide/ hydroxide phases are present and play a role in photoprotection

Diversity and Functional Traits of Lichens in Ultramafic Areas: A Literature Based Worldwide Analysis Integrated by Field Data at the Regional Scale

While higher plant communities found on ultramafics are known to display peculiar characteristics, the distinguishability of any peculiarity in lichen communities is still a matter of contention. Other biotic or abiotic factors, rather than substrate chemistry, may contribute to differences in species composition reported for lichens on adjacent ultramafic and non-ultramafic areas. This work examines the lichen biota of ultramafics, at global and regional scales, with reference to species-specific functional traits. An updated world list of lichens on ultramafic substrates was analyzed to verify potential relationships between diversity and functional traits of lichens in different Köppen–Geiger climate zones. Moreover, a survey of diversity and functional traits in saxicolous communities on ultramafic and non-ultramafic substrates was conducted in Valle d’Aosta (North-West Italy) to verify whether a relationship can be detected between substrate and functional traits that cannot be explained by other environmental factors related to altitude. Analyses (unweighted pair group mean average clustering, canonical correspondence analysis, similarity-difference-replacement simplex approach) of global lichen diversity on ultramafic substrates (2314 reports of 881 taxa from 43 areas) displayed a zonal species distribution in different climate zones rather than an azonal distribution driven by the shared substrate. Accordingly, variations in the frequency of functional attributes reflected reported adaptations to the climate conditions of the different geographic areas. At the regional scale, higher similarity and lower species replacement were detected at each altitude, independent from the substrate, suggesting that altitude-related climate factors prevail over putative substrate–factors in driving community assemblages. In conclusion, data do not reveal peculiarities in lichen diversity or the frequency of functional traits in ultramafic areas

Contributions to a revision of Cercidospora (Dothideales), 2: Species on Lecanora s. l., Rhizoplaca and Squamarina

A study on the taxonomy, morphology and anatomy of the lichenicolous species of the genus Cercidospora (Dothideales, incertae sedis) growing on lichens of the genera Lecanora (Lecanoraceae), specifically of the L. polytropa group and the L. saxicola group (i.e. L. muralis sensu auct. group, Protoparmeliopsis spp.), Rhizoplaca (Lecanoraceae) and Squamarina (Stereocaulaceae) is presented. The following species are proposed as new: Cercidospora barrenoana on Rhizoplaca peltata, and C. melanophthalmae on Rhizoplaca melanophthalma. C. stenotropae is proposed provisionally; this fungus grows on Lecanora stenotropa and other taxa of the L. polytropa group. A key for the species of the genus Cercidospora treated is provided. Key words – Ascomycota – lichenicolous fungi – lichenized fung

Sagenidiopsis, a new genus of byssoid lichenized fungi

The genus Sagenidiopsis gen. nov. of uncertain family in the order Opegraphales is erected for a byssoid lichen which occurs in the cool temperate rainforests of the Macpherson Range of eastern Australia, S. merrotsii sp. nov. The genus is characterized by its byssoid thallus and bitunicate asci which have no amyloid structures apparent in the tholus. A byssoid thallus is without taxonomic significance at the family level, but is an ecological key character