Two new semi-cryptic species from the marine littoral zone of NW Europe, Hydropunctaria oceanica and H. orae, are described. Both differ from H. maura in their ITS and mtSSU sequences and in their thinner thalli and H. orae also differs in its green rather than brown cortical pigment. Hydropunctaria aractina comb. nov. is reinstated as an accepted species, but is difficult to distinguish from H. orae by morphology alone. Lectotypes and epitypes are proposed for H. aractina and H. maura.

Fuscopannaria confusa is a rare lichen restricted to very humid localities in boreal forests. Two Fuscopannaria species, F. ahlneri and F. mediterranea, and Parmeliella parvula are morphologically problematic to distinguish from F. confusa. Our aim with the present study was to evaluate the taxonomic status of F. confusa and thereby clarify its conservation status in Norway. By phylogenetic analysis of multi-locus DNA sequences, we show that F. confusa is genetically well distinguished from F. ahlneri,F. mediterranea, and P. parvula. Fuscopannaria confusa should therefore be treated as a separate species. A species distribution modelling analysis indicates that F. confusa has a slightly continental but potentially wide geographic distribution in Norway. However, suitable localities are continuously being destroyed by clear-cut logging and hydroelectric power development. Because of the decline in suitable habitats, F. confusa should be regarded as highly threatened in Norway and listed as EN (endangered) at the national level.

The new taxa Cliostomum subtenerum, Dactylospora suburceolata, Fuscidea oceanica, Lecania granulata, Lecidea herteliana, and Ropalospora lugubris f. sorediata are described from collections made from Scotland and Wales. Outside the British Isles, D. suburceolata is also known from Switzerland, L. herteliana from NE North America and R. lugubris f. sorediata from Sweden and NE North America. In addition, Lecidea luteoatra Nyl. belongs to the Lecanora marginata group and the name Lecanora viridiatra (Stenh.) Nyl. is taken up for this species, Peterjamesia sorediata is transferred to Roccellographa, and Ropalospora atroumbrina is included in the synonymy of R. lugubris f. sorediata.

The new species Fellhaneropsis rhododendri is described from living Rhododendron leaves in the Netherlands. It is characterized by pyriform pycnidia with stiff, septate hairs at the mouth. It is doubtlessly due to recent global warming that an obligately foliicolous lichen can be described from a temperate area in Europe.

Twenty species of lichenicolous fungi are reported on Thamnolia species and discussed. Epithamnolia karatyginii gen. et sp. nov., Capronia thamnoliae sp. nov., Cercidospora epithamnolia sp. nov., C. thamnogalloides sp. nov., C. thamnoliae sp. nov., and Sphaerellothecium thamnoliae sp. nov. (var. thamnoliae, var. taimyricum) are described from Thamnolia. Dacampia thamnoliicola and Phoma thamnoliae are introduced ad interim. Cercidospora lecidomae is reduced to synonymy with C. punctillata. Polycoccum vermicularium is new to Asia, Odontotrema santessonii and O. thamnoliae are new to North America, Cladosporium licheniphilum is new to the Arctic, Thamnogalla crombiei is new to Greenland and Svalbard, Stigmidium frigidum is new to Mongolia and confirmed in the USA, Lichenopeltella thamnoliae is new to Bolivia. Cladosporium licheniphilum and Phaeospora arctica are newly documented on Thamnolia and Lichenopeltella thamnoliae on Thamnolia papelillo var. subsolida. Thamnolia vermicularis, supporting 23 species of lichenicolous fungi, is shown to be the 15th most hospitable lichen species in the world. A worldwide key to 23 species of fungi known to occur on Thamnolia is provided.

The lichen Pyrenula minutissima is described as new to science from the Hyrcanian forests in northern Iran. In addition, three further, essentially tropical, Pyrenula species are reported for the first time from Iran. An identification key is provided for all eight Pyrenula species now known from Iran.

Lecania chlorotiza and L. falcata, described here as new from Spain/Navarra, the Canary Islands and the Azores, do not belong to Lecania s. str. They belong to a strongly supported clade comprising Bacidia, Bacidina, Scutula and Toninia when examined with maximum parsimony, maximum likelihood and Bayesian inferences using mtSSU, nuLSU and nuITS sequences. This clade represents the Bacidiaceae and is included in the Ramalinaceae s. lat. Most genera included in that family need further work before a new genus can possibly be described for Lecania chlorotiza and L. falcata.

A new isidiate, xanthone-producing species, Rinodina chrysidiata, is described and compared in detail with R. xanthophaea, a species with which it co-occurs in eastern Asia. The two species have an identical chemistry but are clearly separated by their differing lichenized diaspores, thallus morphology and ascospore type.

An identification key is presented for the accepted species of the lichen genera Anthracothecium (comprising 5 species) and Pyrenula (with 169 species, including 7 still undescribed). The key also contains some similar taxa and is complete for Blastodesmia (1 species), Sulcopyrenula (4 species), and Eopyrenula (6 species), but not for others such as Aptrootia, Architrypethelium, and Lithothelium, of which only the corticolous brown-spored taxa are treated. The following new combinations were found to be necessary: Anthracothecium interlatens (Nyl.) Aptroot, Pyrenula breutelii (Müll. Arg.) Aptroot, Pyrenula ceylonensis (Ajay Singh & Upreti) Aptroot, Pyrenula fusispora (Malme) Aptroot, Pyrenula gibberulosa (Vain.) Aptroot, Pyrenula lyoni (Zahlbr.) Aptroot, Pyrenula papillifera (Nyl.) Aptroot, Pyrenula platystoma (Müll. Arg.) Aptroot, Pyrenula schiffneri (Zahlbr.) Aptroot, Pyrenula welwitschii (Upreti & Ajay Singh) Aptroot, and Sulcopyrenula subglobosa (Riddle) Aptroot. Pyrenula sexluminata Aptroot is a new name for Pyrenula quinqueseptata Aptroot, and Pyrenula neosandwicensis Aptroot is a new name for Anthracothecium sandwicense Zahlbr. In addition, all known and many novel synonyms are cited, and the disposition of all other taxa in the two genera Anthracothecium (with 155 names) and Pyrenula (with 745 names) and their generic synonyms. Bogoriella was found to be an older name for Mycomicrothelia.

The new species Placopyrenium bullatum is described from limestone in Turkey. It is characterized by the immersed ascomata, the areolate and bullate thallus, the often blackened exciple and the 1-septate ascospores. It resembles P. iranicum, but differs by the 1-septate ascospores, the dark exciple and the black mottled medulla.

Several specimens of a lichen-inhabiting Tremella, inducing the formation of pale yellow, dark brown or black galls on species of Diploschistes, have been collected in three localities in Sweden and in one locality in the USA. Morphological and molecular studies confirm that this material represents a single species, which differs from other described Tremella species in the combination of gall morphology, basidium morphology, basidium and basidiospore sizes, presence of thick-walled hyphidia, and a different host-selection. We consequently describe this fungus as Tremella diploschistina sp. nov., on the basis of morphology and phylogenetic analyses of ITS and nLSU sequences. The phylogenetic analyses reveal that the fungus clearly belongs in Tremella, although the relationships with other species in the genus remain unclear.

With 30 species, Tasmania is a major area of species diversity in the genus Menegazzia. Seven of these are new to science: M. abscondita Kantvilas, known from Tasmania and New Zealand, and M. athrotaxidis Kantvilas, M. hypogymnioides Kantvilas, M. petraea Kantvilas, M. ramulicola Kantvilas, M. subtestacea Kantvilas and M. tarkinea Kantvilas, all endemic to Tasmania. An identification key, descriptions based exclusively on Tasmanian collections, and detailed discussion of distribution, ecology, chemical composition and inter-species relationships are provided. All literature records of Menegazzia species pertaining to Tasmania are accounted for. New synonyms include: Menegazzia prototypica P. James and Parmelia pertusa var. coskinodes F. Wilson [synonyms of M. myriotrema (Müll. Arg.) R. Sant.], M. fertilis P. James [a synonym of M. platytrema (Müll. Arg.) R. Sant.] and Parmelia pertusa var. montana F. Wilson (a synonym of M. subtestacea). Incorrectly recorded species that should be deleted from the Tasmanian census include M. castanea P. James & D. J. Galloway (present on Macquarie Island) and M. testacea P. James & D. J. Galloway (endemic to New Zealand). The South American species, M. sanguinascens (Räs.) R. Sant., is recorded in Australasia (Tasmania) for the first time, whereas the widespread south-eastern Australian M. norstictica P. James is recorded for Western Australia. Salient features of the genus are discussed, including morphology, anatomy and chemistry. The biogeography of the genus is explored briefly. Twelve species (40%) are endemic to Tasmania, a level of endemism unmatched by any other species-rich genus on the island. Twelve species are shared with mainland Australia, eleven are shared with New Zealand, and only four species are shared with southern South America, all of which are sorediate, suggesting they are products of long-distance dispersal.

Bacidina flavoleprosa is described as a new species from the Czech Republic. Its position within the genus is supported by phylogenetic inferences of ITS rDNA sequences from its holotype and many other representatives of Bacidia s. lat., including newly sequenced Bacidina sulphurella, B. adastra and B. neosquamulosa, as well as additional sequences of B. arnoldiana. ITS data also support the recent delimitation of B. arnoldiana and B. sulphurella based on the shape of conidia and ecological preferences.

Agonimia flabelliformis sp. nov. (Verrucariaceae, Ascomycota) is described as a new species from the Czech Republic, Germany and Great Britain. Except for the distinctive, flabelliform to minutely coralloid thallus the species mostly resembles A. allobata. It differs from other related species of Agonimia in the absence of cortical papillae and in ascospore size. The distinctness of the new species and its placement within the genus Agonimia is supported by analyses of mitochondrial small subunit ribosomal DNA sequences from several samples of the taxon, and from many other representatives of Verrucariales including newly sequenced A. repleta and A. vouauxii. Additionally, ITS rDNA sequence data supports the distinction of A. flabelliformis from A. allobata. However, A. allobata was found to be highly variable and relationships, as well as the monophyly of taxa within Agonimia, are still unresolved and need further investigation.

Plectocarpon dirinariae Ertz & van den Boom is described from Cape Verde from the thallus of saxicolous Dirinariaapplanata. The new species is characterized by convex rounded ascomata not inducing basally constricted galls, non-carbonized sterile stromatic tissue, mainly 4–6-spored asci and 3-septate ascospores. Similar Plectocarpon sp. are discussed.

Pertusaria etayoi, found on lava flows and basaltic rocks from the Canary Islands, is described as new to science. It is the only species in the group of saxicolous Pertusaria with verruciform apothecia and 2 rough-walled ascospores to contain thiophaninic acid. A description of the species is given together with notes on its chemistry, distribution, ecology and taxonomy. Possible related lichen taxa are discussed briefly.

Trapeliopsis gymnidiata, a terricolous species from the Canary Islands, is described as new to science. It has previously been confused with T. wallrothii, but differs by the soft, partly decorticate isidia, or rather gymnidia, that leave inconspicuous scars after falling off. Trapeliopsis wallrothii is known only from high mountains in Macaronesia, while T. gymnidiata is a lowland species. Trapelia rubra from Madeira is also described as new to science. It grows in similar places and resembles some morphs of Trapelia coarctata, but differs by the nearly squamulose areoles, the crenulate, seemingly sorediate, apothecium margin that does not become excluded, and especially by the patchy red colour (skyrin) in the medulla.

Morphological and chemical studies of Hypogymnia from the Himalayas revealed one new species, three species new to the region, and a previously unrecognized synonym. Hypogymnia crystallina, distinguished by its rimmed holes in the lobe axils, a pruinose disc, POL+ epihymenium, and distinctive chemistry (zeorin, hypoprotocetraric acid, usnic acid and atranorin) is described as new. Hypogymnia pseudohypotrypa (Asah.) A. Singh is synonymized with H. thomsoniana and a second location is reported for the recently described H. sikkimensis. Hypogymnia bitteri, H. mundata, and H. subarticulata are reported as new to India. A total of 17 species of the genus Hypogymnia are accepted for the Himalayan region of India and Nepal, with one additional species from southern India. A key is given to the species known from this region.

Diploschistes albopruinosus is described as new to science. This species is found on siliceous rocks in La Caldera de Taburiente National Park (La Palma, Canary Islands). A description of the species is given together with notes on its chemistry, distribution, ecology and taxonomy. Related lichen taxa are discussed.