Species of Physcia reported to have a paraplectenchymatous lower cortex appear to have a dual cortex consisting of a lower paraplectenchymatous layer and an upper periclinally arranged prosoplectenchymatous layer. These species may have a black or pale lower surface but always contain atranorin. They should be retained in the genus Physcia.

Micarea xanthonica sp. nov. is described from the western British Isles, westernmost Norway and the Pacific Northwest of North America. It belongs to the M. prasina group, but differs from related species in possessing xanthones in the thallus.

A laboratory experiment was conducted to determine the damage caused by snail grazing to 35 calcicolous lichen species and cyanobacteria from the Baltic island of Oland, Sweden. Individuals of four species of land snails (Balea perversa, Chondrina cliema, Clausilia bidentata and Helicigona lapicida) were allowed to graze on identified lichen species growing on pieces of limestone. Snail grazing on thalli and ascocarps was classified into four categories ranging from no damage to completely eaten. In general, some lichen species were heavily grazed, whereas others were only slightly damaged or not injured. Aspiciha calcarea, Tephromela atra and Verrucaria nigrescens were preferred by all snail species except Chondrina cliema. In general, lichen thalli that were not immersed in the calcareous rock and cyanobacteria were preferred, whereas ascocarps were avoided by one of the snail species (C. clienta). Immersed perithecia with a carbonized outer layer were avoided by all snail species except C. bidentata. Possibilities of chemical and mechanical defence properties in calcicolous lichens are discussed.

Cladonia arbuscula subsp. squarrosa (Wallr.) Ruoss and C. stygia (Fr.) Ruoss are reported for the first time from the Southern Hemisphere. Populations of C. arbuscula in New Zealand and Australia are recognized as subsp. stictica Ruoss, subsp. nov., usually containing stictic acid, norstictic acid (first report in subg. Cladina), and sometimes also the fumarprotocetraric acid complex. C. laevigata (Vainio) Gyelnik is reinstated in Cladonia subg. Cladina sect. Tenues, while C. stygia is considered to belong to sect. Crustaceae rather than to sect. Tenues. C. confusa R. Sant. is morphologically highly variable, although chemically uniform, usually containing usnic acid and perlatolic acid. An usnic acid-deficient chemodeme is reported as new to New Zealand.

Pannaria isabellina is transferred from Psoroma to Pannaria as it lacks the amyloid apical ascus structure characteristic of Psoroma. However, it has an isolated position within Pannaria because of its lichenized squamules developing horizontally on a thin, filmy prothallus, and its thallus chemistry characterized by the norstictic acid chemosyndrome. It also has a sclerenchymatous epicortex and a characteristic perispore with gibbose wall swellings and long flagella-like apical extensions; both characters are not often found and are still insufficiently studied within the genus Pannaria. The gelatinous, long flagella-like apical extensions of the perispores probably serve to anchor the ascospores to thin and vertical substrata; the species seems to be concentrated in forest margins of evergreen forests along the coast of Chile, except in the Valdivian rainforest region where it extends further east.

The new species Sticta viviana A. Suárez & Lücking is described from Colombian paramos. It superficially resembles S. fuliginosa s. str. but differs by the small lobes with a shiny surface, the strongly branched, corymbose isidia, the dark lower tomentum, the smaller, usually sessile and urceolate cyphellae with one papilla-like outgrowth per cell of the basal membrane, and the K+ orange-yellow medulla. In contrast, Sticta fuliginosa s. str., as represented by the type material, a sequenced topotype, and specimens from North America and Colombia falling into the same clade, is defined by an uneven lobe surface, simple to branched but not corymbose isidia, a pale lower tomentum, larger, immersed to erumpent cyphellae, with each cell of the basal membrane having 2–4 papillae, and a K− medulla. The new species is not closely related to S. fuliginosa s. str. but falls within a clade of several, as yet undescribed, species with S. fuliginosa gross morphology.

Numerous recent studies of lichenized fungi have uncovered hidden genetic diversity within a single phenotypic entity (so-called ‘cryptic species’). Here we report the opposite situation with vastly different morphologies apparently deriving from the same genotype. Endocena is a monotypic genus known only from southern South America. The single reported species, the terricolous E. informis, is morphologically variable; the type and other collections from the west coast of Chile being subfruticose, whereas specimens from further south and east are almost crustose in form. A sorediate terricolous lichen that is frequent on the Falkland Islands was confirmed by phylogenetic analysis of ITS rDNA and mtSSU rDNA sequences as being congeneric with E. informis and, surprisingly, both taxa were recovered as congeneric with the recently described genus and species Chirleja buckii, which is morphologically distinct from both E. informis and the sorediate taxon. Consequently, the genus Chirleja is included in the synonymy of Endocena and the new combination Endocena buckii is proposed. Because E. informis and the sorediate specimens have a similar thallus structure that differs radically from that of E. buckii, the name E. informis var. falklandica is proposed for the sorediate taxon. Poorly developed, incipient apothecia are also described from both varieties of E. informis, the first time that these have been reported for Endocena. We also report two lichenicolous fungi from E. informis var. informis, which are the first reports of lichenicolous fungi occurring on this genus.

Two new conidial lichenicolous fungi are described from Spain: Lichenodiplis crespoae on Cyphelium notarisii and Minutoexcipula tephromelae on Tephromela atra. Lichenodiplis crespoae differs from all the described species of the genus in the narrower and shorter conidia, and the host Cyphelium notarisii. Minutoexcipula tephromelae is characterized by subglobose, conidiogenous cells occasionally bearing 1–2 long proliferating extensions, short conidia and by the host Tephromela atra.

Over the last decades, levels of sulphur deposition from air pollution have been substantially reduced in Norway, whereas levels of nitrogen deposition have been stable or somewhat increased. In parallel, a clear trend of increasing annual temperatures, as well as precipitation, is evident. Human impact on natural ecosystems is predicted to reduce biodiversity at regional scales through facilitating a few generalist species at the expense of species with narrow habitat requirements. In this study, we investigate changes in community composition and the abundance of dominant lichen species on birch in subalpine forests over a 15-year period. The study is based on repeated measurements in five monitoring sites in Norway, representing regional gradients in temperature and precipitation as well as in deposition of nitrogen and sulphur compounds. Two dominant species are studied in particular; the generalist Hypogymnia physodes and the subalpine birch specialist Melanelia olivacea. The largest change in species composition was found in the site with the biggest reduction in sulphur deposition during the 15-year period, whereas the site with low precipitation and low pollution loads had small changes in species composition. The abundance of the generalist H. physodes increased in all sites and the specialist M. olivacea decreased in abundance, especially in sites with both high precipitation and heavy nitrogen deposition. Our study thus suggests that a warmer, humid climate is beneficial for the generalist H. physodes.

Four species of Eschatogonia are recognized in Peru: E. angustiloba Timdal sp. nov., E. dissecta Timdal & R. Sant. sp. nov., E. minuta Timdal & R. Sant. sp. nov., and E. prolifera (Mont.) R. Sant. African and South American material of E. prolifera are shown to belong in two different chemical strains. Eschatogonia prolifera is new to Guinea, Peru and Suriname. A key to all six known species of the genus is given.

The cryptogamic vegetation, dominated by lichens, in a secondary coastal dune area is described. The Coelocaulon aculeatum community colonizes large exposed sand patches. The Cladonia glauca–C. mitts community colonizes where litter has accumulated. The Cladonia mitis and C. portentosa communities occupy more sheltered sites than the Coelocaulon aculeatum community. The scattered Cladonia zopfii community colonizes both exposed and slightly more sheltered sand patches. The common Cladonia uncialis–C. mitis community usually colonizes smaller sand patches with some humus accumulation than those colonized by the Coelocaulon aculeatum community. The Cladonia mitis, the C. portentosa and the Cladonia uncialis–C. mitis communities and probably the Cladonia zopfii community are suggested to be final stages in the lichen succession.

Fellhanera gyrophorica Sérus., Coppins, Diederich & Scheidegger is described as new from Europe Austria, Lithuania, Luxembourg, Poland, Switzerland and Ukraine. It is a sterile corticolous species with conspicuous and sometimes shortly stalked pycnidia whose outer walls produce gyrophoric acid. Its position in the genus Fellhanera (Pilocarpaceae) is tentative and further studies may necessitate its transfer to another genus.

The cortical structure of Usnea subfloridana and algal cell division within the thallus, is illustrated and described.

We present a survey of the six known species of Anhothelium occurring in the western Mediterranean. The oceanic A. lirellans, which may occur in the study area, is included for comparison; A. taediosoides is described as new and a key to all species is given. Anhothelium as understood today is composed of more-or-less distinct natural groups of species, some of them being compared here. Representatives of the A. sardoum group are related to species of the Arthonia radiata or A. galactites group on the basis o anatomical characters of the ascomata.

Lecanora compallens and L. sinnosa, two corticolous lichens, are described nas species new to science on the basis of numerous collections. Lecanora compallens is a sorediate species, known only as sterile. It is probably common in Western Europe, but overlooked because it is very similar to L. expallens. Chemically, the new species is identical with L. strobilina, of which it may represent a sorediate counterpart. Lecanora sinuosa is a new species similar to L. chlarotera and so far only known from a limited area in the Netherlands and Germany, although it may be overlooked elsewhere. Lecanora sinuosa is very close to L. hybocarpa with which it shares the puhcaris-type epihymenium inspersed with fine crystals but differs markedly by its thick thallus and thick and sinuous apothecium margin.

Usnea is a species-rich and widespread lichenized fungal genus of well-lit parts of forest canopies (Motyka 1936, 1947; Clerc 1998). The bright greenish colour of these beard lichens reflects the presence of usnic acid in the cortex, which forms a thin, but dense sleeve around the trebouxioid photobiont in the outermost parts of the medulla. Usnic acid, a widely distributed dibenzofuran derivative produced by various mycobiont genera, strongly absorbs UV-B, but also the shortest PAR wavelengths (e.g. McEvoy et al. 2006, M. McEvoy, K. A. Solhaug and Y Gauslaa unpublished). Depending on species (Halonen et al. 1998), Usnea also contains a wide range of UV-B absorbing depsidones and depsides, though these are usually assumed to be confined to the medulla. Quantitative data on lichen compounds are rare in Usnea species, particularly with respect to the intrathalline variation.

A new cyanolichen, Peltigera islandica sp. nov. in the section Peltigera (‘P. canina group’) is described from Iceland. This species is similar in general appearance to P. rufescens and P. membranacea, but may be recognized by its downturned lobe tips and narrow lobes, respectively. Most thalli are bright emerald green in colour when moist, although a dark khaki green colourmorph is also documented. Monophyly of P. islandica s. lat. (i.e. including P. sp. A sensu O’Brien et al., from Canada) is significantly supported based on ITS sequences and corroborated by molecular synapomorphy (absence of the ITS1 hypervariable region). Analysis of the rbcLX locus indicates the cyanobiont of P. islandica (Nostoc sp.) comprises strains belonging to a pool of Icelandic genotypes, some of which are present in other Peltigera species, including P. “neorufescens”, another taxon new to Iceland collected during this study. Association with photobionts that are shared by other local species suggests P. islandica may be well established in Iceland, but a review of herbarium collections as well as broader field surveys are needed to better characterize its geographical distribution.