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.

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.

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.

The Caloplaca holocarpa group contains members of the family Teloschistaceae with a strongly reduced thallus and conspicuous yellow, orange or red apothecia. In the absence of well-defined thallus characters, taxa of this group must be identified mainly by apothecial characters and are as a result often difficult to separate. The species of this group have been shown not to form a monophyletic entity, with representatives of other Teloschistaceae with more complex thalli intermixed among them. Caloplaca skii and C. syvashica are recognized here as two homogeneous clades with Caloplaca holocarpa-like phenotypes. Caloplaca skii, which is widespread in southern Europe, resembles C. cerinelloides but is distinguished by its smaller and narrower ascospores and by growing predominantly on xerophilous shrubs. Caloplaca syvashica is restricted to shrubs in salt marshes in the northern Black Sea region. It is similar to the British Caloplaca suaedae and Australian C. yarraensis, but differs from both, mainly in ascospore characters. Caloplaca yarraensis is closely related to the new C. syvashica but arguments against their conspecificity are emphasised. A key for epiphytic C. holocarpa-like Teloschistaceae from Europe is provided.

The new genus, Cameronia Kantvilas, is described and illustrated. It is characterized by a crustose thallus, a chlorococcalean photobiont, deeply immersed perithecioid ascomata, four-spored asci with an intensely hemiamyloid outer wall and non-amyloid, well-developed tholus, and hyaline, muriform ascospores. The taxonomic position of the new genus is uncertain although a relationship with the Ostropomycetidae is likely. Two species, both endemic to the highlands of Tasmania, are described: C. pertusarioides Kantvilas, which is one of the most common lichens on dolerite in alpine Tasmania, and C. tecta Kantvilas, which is confined to metamorphosed sediments.

A preliminary study of the Lecanora dispersa group in Argentina is presented. Two species (L. dispersa and L. hagenii) have been previously recorded and their known distribution is extended, one species (L. semipallida) is a new record from Argentina, and five taxa (L. flowersiana, L. persimilis L. torrida, L. wetmorei and L. zosterae var. zosterae) are reported for the first time from South America. Three species (L. albescens, L. crenulata and L. populicola) previously recorded for Argentina have not been confirmed as occurring in this country. Lecanora aff. fugiens is also treated and compared to the related species. The morphology, anatomy, secondary metabolites, distribution and ecology of the nine studied taxa are described and discussed, and a key to the taxa is included.

The new genus Malmographina Cáceres, Rivas Plata & Lücking is introduced for Opegrapha plicosa Meissn. (syn. Graphis malmei Redinger), with the new combination Malmographina plicosa (Meiss.) Cáceres, Rivas Plata & Lücking. The taxon is characterized by prominent, striate, orange-pigmented, non-carbonized lirellae, a more or less clear hymenium, and large, muriform, hyaline ascospores. Malmographina is most similar to Hemithecium in lirellae morphology and anatomy, but in a molecular phylogenetic analysis falls within a clade containing Phaeographis and other genera with usually inspersed hymenium and brown ascospores. Within that clade, it is thus far the only taxon that has persistently hyaline ascospores. It is otherwise similar to Pallidogramme but does not cluster within that genus. A preliminary phylogenetic analysis of the Phaeographis clade confirms monophyly of the genera Halegrapha, Pallidogramme, and Platygramme, and suggests that Phaeographis should be divided into several generic lineages and that Leiorreuma and Sarcographa perhaps be merged.

Phenotypic characters, either morphological or chemical, have shown to be insufficient to delimit species boundaries in the genus Cladonia. The present study addresses the circumscription of species within the Cladonia cariosa group, examining a number of specimens of the currently accepted taxa Cladonia cariosa, C. symphycarpa, C. acuminata, C. subcariosa and C. latiloba. We employed maximum likelihood and Bayesian methods of phylogenetic reconstructions based on DNA sequences of ITS, rpb2 and ef1α regions. Our results show that the C. cariosa group consists of at least four phylogenetic lineages. It is also shown that each of these lineages is chemically variable, which restricts the taxonomic value of the chemical differences within the group. However, anatomical differences, such as squamule surface and cortex structure, were found to correlate with the distinct lineages found in the phylogenetic analysis. This result confirms the taxonomic value of the cortical surface under SEM, as was found in other lichen groups.

Although various eukaryotic organisms, such as arthropods, endolichenic/lichenicolous fungi, and nematodes, have been isolated from lichens, the diversity and structure of eukaryotic communities associated with lichen thalli has not been well studied. In addressing this knowledge gap, we used bar-coded pyrosequencing of 18S rRNA genes to survey eukaryotes associated with thalli of three different lichen species. In addition to revealing an expected high abundance of lichen biont-related 18S genes, sequences recovered in our survey showed non-biont fungi from the Ascomycota also have a substantial presence in these thalli. Our samples additionally harboured fungi representing phyla (Blastocladiomycota, Chytridiomycota) that have not been isolated previously from lichens; however, their very low abundance indicates an incidental presence. The recovery of Alveolata, Metazoa, and Rhizaria sequences, along with recent work revealing the considerable bacterial diversity in these same samples, suggests lichens function as minute ecosystems in addition to being symbiotic organisms.