This paper reassesses the southern temperate South American and Australasian species of Nephroma, analyses their chemistry and provides a key to the 14 species and three varieties accepted. N. occultum from North America is also discussed due to its close relationship to N. microphyllum and N. papillosum. Three pairs of morphotypes are described for the first time: N. analogicum-N. chubutense, N. kuehnemannii-N. microphyllum and N. skottsbergii-N. papillosum. N. papillosum sp. nov. and N. skottsbergii sp. nov. from Chile and Argentina are newly described. N. lobuligerum and N. lepidophyllum are reduced to varietal rank. N. lyallii is placed in synonymy with N. plumbeum and a new combination N. plumbeum var. isidiatum (J. Murray) F. J. White & P. James is made.

A new genus, Catenarina (Teloschistaceae, Ascomycota), with three species is described from the Southern Hemisphere, supported by molecular data. All species contain the secondary metabolite 7-chlorocatenarin, previously unknown in lichens. Catenarinadesolata is a non-littoral, lichenicolous species found on volcanic and soft sedimentary rock at 190–300 m in and near steppes in southernmost Chile and on the subantarctic island, Kerguelen. Catenarina vivasiana grows on maritime rocks and on rock outcrops in lowland Nothofagus forests, but has also been found at altitudes up to c. 580 m on moss and detritus on outcrops in Tierra del Fuego. The Antarctic species Caloplaca iomma is transferred to Catenarina based on chemical data; it grows on rocks near the coast in maritime Antarctica.

In this investigation we utilized parsimony and Bayesian analyses of mtSSU and nuLSU rDNA sequence datasets to show that the lichenized ascomycete genera Leptochidium and Polychidium (formerly classified in Placynthiaceae) form a well-supported monophyletic group with Massalongia (Peltigerales, Lecanoromycetes, Ascomycota). This group is also supported by morphological characteristics (ascus type, ascoma ontogeny and anatomy), but does not have a formal name on any level. We describe it here as the family Massalongiaceae. Massalongiaceae is related to a group consisting of Peltigeraceae-Nephromataceae, and Lobariaceae, but the detailed relationships within this group are not resolved with convincing support.

Relative growth rates (RGR) and carbon-based secondary compounds (CBSCs) were quantified in four dominant terricolous arctic-alpine mat-forming lichens with different preferences for snow cover. The aim was to evaluate the effects of snow depth, and thus snow cover duration, on lichen growth and performance. The species, Alectoria ochroleuca, Flavocetraria nivalis, Cladonia mitis and Cetrariella delisei, are associated with increasing snow depth, respectively. They were transplanted for one year at five snow depths (0, 60, 120, 160 and 200 cm measured in early May) along each of four natural ridge to snow bed gradient transects in oceanic-alpine sites (western Norway). Snow slightly thicker than in source habitats caused negative RGR in the ridge top-dependent A. ochroleuca and the co-occurring F. nivalis with somewhat higher snow tolerance. Only C. mitis with the broadest ecological niche had positive RGR along most of the gradients (0–160 cm), even outside its natural range. The most snow-tolerant species, C. delisei, tolerant also to temporal inundation in water, had the lowest RGR. Nevertheless, it performed as well in places with little or no snow as in places where it grows naturally. Snow depth significantly affected total concentrations of CBSCs mainly in A. ochroleuca, which experienced substantial mass loss under snow. There was a highly significant increase in usnic acid concentration with increasing mass loss in A. ochroleuca, probably because usnic acid decays more slowly than other components. In conclusion, snow reduced lichen RGR, but in species-specific ways. Therefore, increasing snow depth per se along spatial and/or temporal scales likely reduces abundance and distribution of dominant mat-forming lichens in the alpine ecosystems of Scandinavia.

The study aimed to determine how the response of the epiphytic lichen vegetation to sulphur air pollution is affected by interaction with other factors (distance from pollution sources, habitat, altitude, initial eutrophication of the tree bark). It was based on a series of four successive recordings taken over a period of 18 years with increasing pollution levels and on the same set of 139 solitary trees. Relationships between habitat variables and lichen community composition are assessed using canonical correspondence analysis. The data set comprised 69 lichen species. Ordination of initial species composition on trees revealed two major gradients: eutrophication and acidity.

The species composition significantly changed with time, with a general decrease of the total number of lichen species per tree. In general, species sensitive to air pollution decreased, while tolerant species increased in number. Change over time differed depending on the position of the tree within the landscape (relative to one major source of pollution, the town of Tábor, whereas the distance to the other source, Sezimovo Ústí, was not significant) and on the initial species composition found on the tree. Trees under the effect of eutrophication changed their species composition less, indicating that the effect of eutrophication (mainly increased bark pH) may ameliorate the effects of air pollution; a local effect of eutrophication also seems to play an important role. Distance to pollution sources had only a small impact on the rate of change and perhaps other local conditions (sheltered or humid position, altitude) play a role in this interaction. There was a decrease of the overall heterogeneity of the data set over time. This means that the gradients in species composition attributable to these variables became less important over time. Therefore, one of the effects of air pollution is also a general homogenization of the lichen vegetation of the solitary trees.

The lichenized basidiomycete known as Dictyonemainterruptum is a widely distributed but rare, oceanic, western European species known from the British Isles, the Pyrenees, the Azores, and Madeira. Unfortunately, the name has never been validly published. The species was first described in the cyanobacterial genus Calothrix in 1833, which predates the starting point of heterocystous bacterial nomenclature, 1 January 1886. The epithet was never subsequently included in a validly published binomial and its combination into Dictyonema was therefore invalid as well. There was also controversy about whether the epithet applied to the cyanobacterial photobiont (as originally intended) or to the lichen fungus (as proposed later). Because of the lack of a valid description for this epithet, we have chosen to establish a new name, Dictyonema coppinsii Lücking, Barrie & Genney, for the lichenized fungus at hand, whereas the cyanobacterial photobiont is validated with the genus name Rhizonema Lücking & Barrie, adopting the epithet interruptum for it, and placed in a separate family, Rhizonemataceae Büdel & Kauff ex Lücking & Barrie.

The crustose lichen genus Mycoblastus in the Northern Hemisphere includes eight recognized species sharing large, simple ascospores produced 1–2 per ascus in strongly pigmented biatorine apothecia. The monophyly of Mycoblastus and the relationship of its various species to Tephromelataceae have never been studied in detail. Data from ITS rDNA and the genes coding for translation elongation factor 1-α and DNA replication licensing factor mini-chromosome maintenance complex 7 support the distinctness of Mycoblastus s. str. from the core of the Tephromelataceae, but recover M. fucatus and an undescribed Asian species as strongly supported within the latter group. We propose accommodating these two species in a new genus, Violella, which is characterized by its brownish inner ascospore walls, Fucatus-violet hymenial pigment granules and secondary chemistry, and discuss the position of Violella relative to Calvitimela and Tephromela. We describe the new species Violella wangii T. Sprib. & Goffinet to accommodate a new species with roccellic acid from Bhutan, China, India and the Russian Far East. We also exclude Mycoblastus indicus Awasthi & Agarwal from the genus Mycoblastus and propose for it the new combination Malmidea indica (Awasthi & Agarwal) Hafellner & T. Sprib.

The responses of the nitrophytic green algal lichen Xanthoria parietina to varying nitrogen (N) concentrations were investigated by collecting 67 X. parietina thalli from clay roof tiles from 13 sites in Portugal with different exposures to N. Concentrations of total N, chlorophyll a (a marker for the photobiont), ergosterol (a marker for the mycobiont), and thallus specific weight (TSW; thallus dry weight in relation to surface area) were quantified for each thallus to see how biont investments were related to thallus N concentrations. Thallus N ranged from 11 to 43 mg g−1 DW revealing a wider N concentration range in this lichen compared to other green algal lichen species. Both chlorophyll a and ergosterol concentrations increased with increasing thallus N, with a steeper increase of the photobiont marker. TSW was similar in all thalli without any significant effect of thallus N concentration, suggesting that thallus developmental patterns are similar in low and high thallus N concentrations. The relatively higher resource allocation to the photobiont in relation to the mycobiont with increasing thallus N concentrations is an indication of the capacity of X. parietina to meet the C demands associated with N assimilation. This result is also in agreement with the inter-specific resource allocation pattern for green algal lichens across the same N concentration range.

The biomass of lichens and its vertical distribution on trees were investigated in a > 100-year-old boreal forest in central Finland. The lichen biomass on individual trees was 1292–3669 g tree−1 on Picea abies and 742 g tree −1 on Pinus sylvestris. More than half of the biomass occurred on dead branches. The proportion of Hypogymnia physodes appeared to rise with the canopy height while the other lichens (Platismatia glauca, Bryoria spp. and Pseudevernia furfuracea) decreased. Mean total lichen biomass for sampled trees on an aerial basis was 163 gm −2. The standing crop of litter lichen deposited on ground was about9 gm −2.

The phylogeny of the genus Pertusaria and allied taxa was investigated using nucleotide sequences of the LSU rRNA gene. Sequences from these regions of 15 pertusarialean fungi were aligned to those of three representatives of Agyriales used as outgroup. The alignment was analysed cladistically using maximum parsimony. The Pertusariaceae appear paraphyletic bearing the monophyletic Coccotremataceae on a clade including Ochrolechia and Pertusaria subg. Monomuratae, but monophyly of the family cannot be rejected. The genus Pertusaria is polyphyletic, with the subgenus Monomuratae more closely related to the Coccotremataceae and Ochrolechia than to taxa of the subgenera Pertusaria and Pionospora. Monophyly of the genus Pertusaria is rejected. The monophyly of the subgenera Pertusaria and Pionospora is also rejected. The distribution of selected characters in the Pertusariales is investigated and it is shown that apothecial form and spore wall number have changed in parallel within Pertusaria. The Pertusaria-type ascus is plesiomorphic within the Pertusariaceae and thus cannot be used to circumscribe Pertusaria. The presence of chlorinated xanthones is restricted to Pertusaria s. str

Lichens are a fascinating example of a symbiotic mutualism. It is still uncertain which processes guide fungal-photobiont interactions, and whether they are random or of a more complex nature. Here, the fungal-algal interactions in Ramalina menziesii and co-occurring taxa are analyzed by using DNA sequences of the algal Internal Transcribed Spacer region (ITS), to investigate fungal-algal associations in juvenile R. menziesii and allied species. Algal species were identified by a combination of BLAST searches, median-joining network analysis, and Bayesian phylogenetics. Fungal-algal networks were analyzed for nestedness, both at the species and haplotype level (fungal species vs. algal haplotypes), and the networks were inspected for evidence of compartmentalization. Bayesian phylogenetic trees indicated that the widespread green alga Trebouxia decolorans associated with R. menziesii, as well as six other fungal species. Four additional fungal species interacted with four different species of Trebouxia. Only in one out of ten samples were algal haplotypes shared with the nearest neighbours of juvenile R. menziesii. Fungal-algal species interactions were compartmentalized, while at the level of algal haplotypes, nestedness was found. This pattern is similar to the compartmentalization found in other intimately interacting mutualists.

The new species Bacidia termitophila, Coenogonium coppinsii, Fellhanera termitophila, and Micarea termitophila are described from termite nests in rainforest in Rondônia and adjacent Amazonas. Lichens were found on termite mounds on the ground but most of the species were also found on termite nests on trees. This substratum may serve as the most important locality for terricolous lichens in rainforests, and the natural habitat for species known mostly from road banks.

A photosymbiodeme is described for Peltigera venosa. One member consists of small black squamules containing cyanobacteria whereas the other, the more familiar thallus of the species, contains green algae. New aspects of morphogenetic influences are discussed.

The Southern Hemisphere genus Leioderma Nyl. contains seven species: L. amphibolum (Knight) P. M. Jørg & D. Galloway, L. applanatum sp. nov., L. duplication (Mull. Arg.) comb, nov., L. erythrocarpum (Nyl.) comb, nov., L. glabrum sp. nov., L. pycnophorum Nyl., and L. sorediatum sp. nov. The genus has two subgenera (Leioderma, and Fuscoderma subgen. nov.) distinguished by differences in thallus morphology and the structures of asci and ascospores. Leioderma is closely related to Erioderma but differs in thallus habit, structure of cortex and ascus, and chemistry. Leioderma appears to be a Gondwanan genus. A key is given, and details of anatomy, morphology, distribution, ecology, phytogeography and taxonomy are discussed. A new, Lewderma-like, sorediate Parmeliella, P. subgranulata sp. nov., is described from New Zealand, and the related P. granulata Lamb, is recorded from New Zealand for the first time.

Ramalina species are among the most abundant lichens on the Galapagos Isles. A total of fifteen species have been distinguished, four of which are described as new here: Ramalina darwiniana, R. fragilis, R. furcellangulida and R. polyforma. These new species are considered to be endemic to the Galapagos whereas previous reports refer to relatively common, more widely distributed species. Several other species are reported here for the first time from the Galapagos.

The distribution of crustose Caliciales has been surveyed in 100 spruce forest patches in Sør-Trøndelag, central Norway. Relationships between occurrence of the species and a number of site and stand variables were analysed by detrended correspondence analysis (DCA) and direct gradient analysis. Species diversity7 was significantly higher in old forests and in forests at higher altitudes compared to young forests and forests at lower altitudes. Old trees and snags are considered to be the most important structural components in old forests promoting species diversity of the Caliciales. Threatened or vulnerable species, such as Chaenotheca gracilliina, Cybebe gracilenta, Sclerophora coniophaea and S. peronella were confined to forest on rich soils showing no correlation with forest stand age. Chaenotheca brachypoda and C. trichialis were found to be the most typical old forest species among the Caliciales. Humidiphilous species are considered to be less affected by forestry in a humid climate. A change in forestry practice towards methods imitating the natural dynamic processes is considered necessary to maintain species diversity of the Caliciales in boreal forests.

Two new species of Arthoniaceae are described from old-growth European forests: Arthonia thoriana from Horner Combe in Great Britain and Inoderma sorediatum from the Białowieża Forest in Poland. Phylogenetic analyses using mtSSU sequences were used to determine the generic affiliation of the two species. Arthonia thoriana is characterized by a non-lichenized white thallus, pallid brown, white pruinose ascomata of 0·12–0·30 mm diam., richly anastomosing paraphysoids and (1–2–)3-septate ascospores of 9–12×3·0–3·5 µm. Inoderma sorediatum differs from all other species of the genus by a sorediate thallus and the production of confluentic acid. It is the sister species to I. afromontanum in our phylogenetic analyses. The discovery of the new species supports the high value of these forests for biodiversity action plans. Phylogenetic analyses also place Schismatomma niveum in the Arthoniaceae and the new genus Snippocia is described to accommodate it. The genus Leprantha is resurrected for its type species (L. cinereopruinosa). A lectotype is designated for Arthonia pruinosella.

This study aims to quantify the size-dependency of important hydration traits in Lobaria amplissima, L. pulmonaria and L. virens sampled in sympatric populations on deciduous tree trunks in southern Norway, and to discuss possible implications of species-specific traits for the ecological niches of these old forest cephalolichens. Traits measured were thallus size (area and mass), specific thallus mass (STM), internal (WHCinternal) and external water-holding capacity (WHCexternal), and water content (WC) after shaking and after blotting. Lobaria amplissima had the highest WHCinternal, 2·6 times higher than L. pulmonaria with the lowest WHCinternal. WHCinternal, driven by STM, strongly depended on size. WHCexternal was 28% (L. virens) to 47% (L. pulmonaria) of the WHCinternal. Unlike WHCinternal, WHCexternal did not depend on thallus area, meaning that WHCexternal is proportionally higher for smaller compared with larger thalli. The most widespread species, L. pulmonaria, benefits from a flexible hydration strategy due to low STM, facilitating the use of more diverse water sources than the other two species that depend more on rain, particularly L. amplissima with the highest STM and thus relatively high WHCinternal. For L. virens, a combination of less specialized hydration traits and a low tolerance to higher light intensity probably jeopardizes its survival outside rainforest habitats.

Ostropales, in a wide sense, currently encompasses Ostropales s. str., with a few lichenized genera, and Graphidales, most of which are lichenized. Conotrema is the only lichenized genus undoubtedly placed in Ostropales s. str. We have sequenced the 18S rRNA gene from some key taxa to answer the questions as to whether one ortwo orders should be recognized and whether Conotrema should be kept in Ostropales if Graphidales is recognized. We have new sequences from Conotrema populorum (Stictidaceae, Ostropales), Cyanodermella viridula (Stictidaceae Ostropales), Graphis scripta (Graphidaceae Graphidales) and Diploschistes ocellatus var. almeriensis (Thelotremataceae Graphidales). In an analysis with 41 taxa, thelichenized D. ocellatus var. almeriensis and G. scripta are the sister group of the lichenized C. populorum and the non-lichenized C. viridula and Stictis radiata. Together they form a monophyletic cluster supported by a bootstrap value of 82%. Therefore, it is possible to use the ordinal name Ostropales in a wide sense to include the Graphidales. If Ostropales are conceived in a narrow sense, Conotrema should be kept in the Stictidaceae. Eight new PCR primer sequences are reported.