Tremella caloplacae (Zahlbr.) Diederich is a species complex including at least nine different species. Here, we formally describe the new species Tremella elegantis, T. nimisiana, T. parietinae, T. pusillae and T. sorediatae. Tremella elegantis induces galls in the hymenium of Rusavskia elegans and forms 2-celled basidia, where cells rarely elongate and sometimes give the appearance of two immature, independent basidia. Tremella nimisiana has small basidiomata (less than 1 mm diam.), narrowly ellipsoid to pyriform 2-celled, occasionally clavate to subcylindrical 3-celled basidia, and grows in the hymenium of Xanthocarpia species. Tremella parietinae is characterized by the exclusive growth in the hymenium of Xanthoria parietina, the broadly fusiform to ellipsoid probasidia, and the subspherical, pyriform or ellipsoid 2(–3)-celled basidia. Tremella pusillae has ellipsoidal probasidia, 2(–3)-celled pyriform or ellipsoidal basidia that sometimes are constricted at the septum, and grows only on Calogaya pusilla. Tremella sorediatae is characterized by inducing galls on the thallus of Rusavskia sorediata and by pyriform to ellipsoid basidia that sometimes are constricted at the septum. Three species are not formally described and are left unnamed as Tremella sp. 13 on Calogaya biatorina, Tremella sp. 14 on Calogaya decipiens and Tremella sp. 15 on Polycauliona sp. Tremella caloplacae in the strict sense is re-circumscribed as a species confined to Variospora species.

The Rostania occultata species complex (‘Collema occultatum s. lat.’) is revised in Fennoscandia and found to consist of four species, all epiphytes on deciduous trees: Rostania effusa A. Košuth., M. Westb. & Wedin sp. nov., R. occultata (Bagl.) Otálora et al., R. pallida A. Košuth., M. Westb. & Wedin sp. nov. and R. populina (Th. Fr.) A. Košuth., M. Westb. & Wedin comb. nov. Rostania effusa and R. pallida are newly described from humid habitats in old-growth boreal coniferous forests, usually with a mixture of deciduous trees, and from similar areas in the subalpine birch-dominated forests of Fennoscandia. Rostania effusa is characterized by apothecia with red-brown apothecium discs and an excipulum thallinum with a simple pseudocortex and cubic to oblong, muriform spores. Rostania pallida has apothecia with whitish to pale yellowish discs and an excipulum thallinum with a distinct cellular pseudocortex, and ellipsoid, muriform mature spores that are often constricted at the centre. A lectotype is designated for Collema quadratum J. Lahm ex Körb. The new combination Rostania populina is introduced for the species recognized until now as the variety Rostania occultata var. populina (Th. Fr.) Perlmutter & Rivas Plata. A key to the six species in Rostania s. str. is included.

The new genus Australidea Kantvilas, Wedin & M. Svensson is described to accommodate Lecidea canorufescens Kremp., a widespread lichen in temperate Australasia. It is characterized by a crustose thallus with a green photobiont, reddish brown, biatorine apothecia with an internally hyaline, cupulate proper exciple constructed of branched and anastomosing hyphae, mainly simple paraphyses, 8-spored, Porpidia-type asci and simple, hyaline, non-halonate ascospores. A phylogenetic analysis places the new genus in the family Malmideaceae. Lecidea canorufescens Kremp., L. glandulosa C. Knight, L. immarginata R. Br. ex Cromb. and L. intervertens Nyl. are lectotypified. These names, plus L. dacrydii Müll. Arg. and L. eucheila Zahlbr., are all synonyms of Australidea canorufescens (Kremp.) Kantvilas, Wedin & M. Svensson comb. nov. Several genera superficially similar to Australidea, including Malcolmiella Vĕzda, Malmidea Kalb et al. and Myochroidea Printzen et al., are compared. A comprehensive anatomical and morphological description of the genus Malcolmiella, recorded for Tasmania for the first time, is also provided. The new combination M. interversa (Nyl.) Kantvilas, Wedin & M. Svensson is introduced and the names M. cinereovirens Vĕzda and M. cinereovirens var. isidiata Vĕzda are reduced to synonyms. The systematic position of this genus remains unclear, although phylogenetic analysis suggests its affinities lie with a group of genera that includes Bryobilimbia Fryday et al., Romjularia Timdal and Clauzadea Hafellner & Bellem.

The lichenicolous ‘heterobasidiomycetes’ belong in the Tremellomycetes (Agaricomycotina) and in the Pucciniomycotina. In this paper, we provide an introduction and review of these lichenicolous taxa, focusing on recent studies and novelties of their classification, phylogeny and evolution. Lichen-inhabiting fungi in the Pucciniomycotina are represented by only a small number of species included in the genera Chionosphaera, Cyphobasidium and Lichenozyma. The phylogenetic position of the lichenicolous representatives of Chionosphaera has, however, never been investigated by molecular methods. Phylogenetic analyses using the nuclear SSU, ITS, and LSU ribosomal DNA markers reveal that the lichenicolous members of Chionosphaera form a monophyletic group in the Pucciniomycotina, distinct from Chionosphaera and outside the Chionosphaeraceae. The new genus Crittendenia is described to accommodate these lichen-inhabiting species. Crittendenia is characterized by minute synnemata-like basidiomata, the presence of clamp connections and aseptate tubular basidia from which 4–7 spores discharge passively, often in groups. Crittendenia, Cyphobasidium and Lichenozyma are the only lichenicolous lineages known so far in the Pucciniomycotina, whereas Chionosphaera does not include any lichenicolous taxa.

This is the first part of an ongoing taxonomic treatment of Bunodophoron (Sphaerophoraceae, Lecanorales) in the Neotropics, based on the molecular phylogenetic analysis of three markers together with studies of morphology and chemistry, and using the general mixed Yule coalescence (GMYC) method to delimit species boundaries. In the Neotropics, species in this genus grow on the ground or on shrubs in the páramos, and as epiphytes in the montane rainforests. We describe here a new species from the páramos of Colombia, Bunodophoron crespoae Soto, M. Prieto & Wedin sp. nov., and discuss its distinction from another large and common páramo species Bunodophoron flabellatum (Hue) Soto, M. Prieto & Wedin comb. nov. Both species are primarily terrestrial in the páramos, although B. flabellatum may occasionally also grow as an epiphyte. Bunodophoron crespoae is characterized by the white, c. 10–13 cm long, subterete to narrowly flattened, main branches. It differs from the otherwise similar B. flabellatum by being distinctly subterete, more abundantly branched, and by having smaller ascospores. Both are distinguished from the primarily epiphytic B. melanocarpum by the considerably larger thallus size, with the main branches of B. melanocarpum rarely exceeding 3·5 cm in length and 2 mm in width.

We investigated the phylogenetic relationships in the cyanolichen family Placynthiaceae to test the current generic delimitations, where the monotypic Collolechia is currently accepted as distinct, based on differences in ascospores, ascus apex characteristics and the leprose thallus. Bayesian and maximum likelihood phylogenetic analyses of two sequence marker datasets confirmed that Collolechia caesia is nested within Placynthium, and should be called Placynthium caesium (Fr.) Jatta. We reassessed the spore and ascus characteristics and showed that Placynthium caesium falls well within the variation in Placynthium and is thus yet another example of a species that differs from close relatives by its crustose-leprose thallus structure.

The cyanolichen genus Epiphloea is currently included within the Heppiaceae (Lichinomycetes) based on ascus characteristics. The presumed presence of a prototunicate ascus has been used as support for this classification, despite the incongruence with other characters (e.g. spores). Here, we use a molecular phylogeny of the two markers mtSSU rDNA and Mcm7 to investigate the position of Epiphloea. In addition, we have re-investigated the ascus characteristics. Our results place the two species, Epiphloea byssina and E. terrena, within the Collemataceae, nested in Leptogium s. str. The ascus type in both species is shown to be Lecanoralean and similar to the ascus in other Collemataceae, with a strongly amyloid tube-like structure. This observation supports the placement within Lecanoromycetes and refutes the earlier suggested affinities with Heppiaceae and Lichinomycetes. The correct names for these species are Leptogium byssinum and Leptogium terrenum.

The Cladonia furcata complex treated here comprises C. farinacea, C. furcata, C. multiformis, C. scabriuscula, C. stereoclada, and C. subrangiformis. The well-known taxonomic complexity of this group is caused by wide phenotypic variation and high morphological similarity among the species, for which reason we investigated the distribution in the phylogeny of the phenotypic characters traditionally used to distinguish the species in this complex. A phylogenetic analysis of the C. furcata complex is presented here, based on three loci (ITS rDNA, IGS rDNA and RPB2), representing specimens from a broad geographical range (Europe, North America and New Zealand). The phylogenetic reconstructions were performed using Maximum Likelihood and Bayesian analyses. In addition, 14 features traditionally used for species delimitation within this complex were mapped onto the Bayesian phylogeny. All the species currently accepted, with the exception of C. stereoclada, turned out to be polyphyletic. Most of the phenotypic characters studied are highly homoplasious with the exception of the podetium type. The solid podetia represent a diagnostic character of C. stereoclada.

We estimated phylogeny in the lichen-forming ascomycete family Pannariaceae. We specifically modelled spatial (across-site) heterogeneity in nucleotide frequencies, as models not incorporating this heterogeneity were found to be inadequate for our data. Model adequacy was measured here as the ability of the model to reconstruct nucleotide diversity per site in the original sequence data. A potential non-orthologue in the internal transcribed spacer region (ITS) of Degelia plumbea was observed. We propose a revised generic classification for the Pannariaceae, accepting 30 genera, based on our phylogeny, previously published phylogenies, as well as available morphological and chemical data. Four genera are established as new: Austroparmeliella (for the ‘Parmeliella’ lacerata group), Nebularia (for the ‘Parmeliella’ incrassata group), Nevesia (for ‘Fuscopannaria’ sampaiana), and Pectenia (for the ‘Degelia’ plumbea group). Two genera are reduced to synonymy, Moelleropsis (included in Fuscopannaria) and Santessoniella (non-monophyletic; type included in Psoroma). Lepidocollema, described as monotypic, is expanded to include 23 species, most of which have been treated in the ‘Parmeliella’ mariana group. Homothecium and Leightoniella, previously treated in the Collemataceae, are here referred to the Pannariaceae. We propose 41 new species-level combinations in the newly described and re-circumscribed genera mentioned above, as well as in Leciophysma and Psoroma.

Belonia and Pachyphiale were recently shown to be nested within Gyalecta. Here, new combinations and names are introduced for species earlier classified in Belonia: Gyalecta calcicola (Walt. Watson) Baloch & Lücking comb. nov., G. herculina (Rehm) Baloch, Lumbsch & Wedin comb. nov., G. incarnata (Th. Fr. & Graewe) Baloch & Lücking comb. nov., G. lumbrispora (Etayo) Baloch & Lücking comb. nov., G. lyngei Baloch & Lücking nom. nov. (for Belonia arctica Lynge), G. mediterranea (Nav.-Ros. & Llimona) Baloch & Lücking comb. nov., G. nidarosiensis (Kindt) Baloch & Lücking comb. nov., G. pellucida (Coppins & Malcolm) Baloch & Lücking comb. nov., G. russula (Körb. ex Nyl.) Baloch, Lumbsch & Wedin comb. nov., G. uncinata (P. M. McCarthy & Kantvilas) Baloch & Lücking comb. nov., and G. vezdana (Malcolm & Coppins) Baloch & Lücking comb. nov.; and for species earlier placed in Pachyphiale: Gyalecta arbuti (Bagl.) Baloch & Lücking comb. nov., G. gyalizella (Nyl.) Baloch & Lücking comb. nov., G. himalayensis (Vězda & Poelt) Baloch & Lücking comb. nov., and G. ophiospora (Bagl.) Baloch & Lücking comb. nov.

The phylogenetic placement of Collema fasciculare (L.) F. H. Wigg, the most deviating species within Collema (Collemataceae, Lecanoromycetidae), was studied using maximum likelihood and Bayesian analysis of three molecular loci (mitochondrial SSU rDNA, and the protein-coding, nuclear RPB1 and MCM7 genes). Collema fasciculare belongs to Arctomiaceae (Ostropomycetidae) forming a strongly supported monophyletic group with members of Arctomia. The spores, paraphyses, asci and hymenial reactions in Collema fasciculare are similar to other Arctomia, but the ascoma ontogeny is somewhat different. Also C. leptosporum Malme, another species in the Fasciculare group, shows similarities with Arctomia regarding spores and asci. Arctomia is morphologically heterogeneous and the genus is in need of revision. Until then, the species of the Fasciculare group fit best in Arctomia s. lat. and the combinations Arctomia fascicularis (L.) Otálora & Wedin, Arctomia leptospora (Malme) Otálora & Wedin, Arctomia papuanarum (Degel.) Otálora & Wedin and Arctomia uviformis (Hue) Otálora & Wedin are proposed.

The recently described genus Vahliella (Peltigerales, Ascomycetes) has repeatedly appeared outside the Pannariaceae in molecular phylogenies. Here we include data from additional species of the genus and utilize mtSSU rDNA and RPB1 sequences to confirm its placement as the sister to a group consisting of Lobariaceae, Massalongiaceae, Nephromataceae and Peltigeraceae, in the Peltigerales. The new family Vahliellaceae Wedin, P. M. Jørg. & S. Ekman is described for the genus, and its morphological characteristics are briefly discussed.

The new genus Silobia M. Westb. & Wedin is proposed for the Acarospora smaragdula group, which is taxonomically and nomenclaturally revised in Sweden. The proposed taxonomy results from our former molecular phylogeny, together with morphological and anatomical investigations and analysis of secondary metabolites. Seven species are recognized in Sweden in this paper: Silobia dilatata sp. nov., S. myochroa sp. nov., S. rhagadiza comb. nov., S. rufescens comb. nov., S. scabrida comb. nov., S. smaragdula comb. nov. and S. tangerina sp. nov. Acarospora alberti, A. amphibola, A. isortoquensis, A. murina and A. undata are recognized as synonyms of S. smaragdula, Acarospora verruciformis as a synonym of S. scabrida and A. scyphulifera as a synonym of S. rhagadiza. The following names are lectotypified: Acarospora amphibola, A. amphibola f. testacea, A. lesdainii, A. lesdainii var. subochracea, A. murina, A. scyphulifera f. subdiscreta, Endocarpon smaragdulum, Lecanora rhagadiza and Sagedia rufescens. Acarospora scyphulifera is neotypified. Acarospora fusca is excluded from the Swedish checklist as the specimen was found to belong to S. rufescens. A key to the species is presented.

A monograph of the genus Placomaronea is presented; all species described earlier are revised, a total of six species is recognized, and an identification key is presented. In addition to the three previously known species, P. candelarioides, P. lambii and P. mendozae, three new species are described: Placomaronea kaernefeltii is a large rosette-like species known from one locality in northernmost Chile; Placomaronea fuegiana is a bullate, areolate species described from Tierra del Fuego, Argentina; Placomaronea minima is a small, areolate to minutely lobate species described from Chile and Argentina, and is the first species of Placomaronea to be reported from the African continent. In a phylogenetic analysis of nuclear ITS rDNA, Placomaronea is shown to form a monophyletic group within the Candelariales.

The taxonomic and nomenclatural status of the common Scutula (Ramalinaceae, Lecanorales, Ascomycota) parasitizing species of Solorina (Peltigeraceae, Lecanorales) is clarified. The type of Biatorina tuberculosa Th. Fr., which, according to the protologue, was described from a Peltigera, is actually growing on Solorina saccata, and the correct name for this species is here shown to be Scutula tuberculosa (Th. Fr.) Rehm. Lectotypes are designated for Lecidea solorinaria Nyl., Scutula krempelhuberi Körb. and Lecidea solorinicola Vain. Notes on the taxonomy and classification of the genus are given, and a key to the species of Scutula s. str. in the Northern Hemisphere is presented. Scutula tuberculosa is reported as new to Asia and North America.

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.

The new fungus Cercidospora alpina is described from Sweden where it grows on the thallus of the crustose lichen Stereocaulon cumulatum. The ecology and distribution of the new species as well as its morphological similarities to related species are discussed. A key to the known species of Cercidospora occurring in Fennoscandia is provided.

The phylogeny of Lecanoromycetes (Ascomycota, Fungi) is investigated utilizing parsimony and Bayesian Markov Chain Monte Carlo analyses, of combined nLSU rDNA and mtSSU rDNA sequence datasets. The results suggest that Acarosporaceae, Candelariaceae, Phlyctis and Pycnora are not members of the monophyletic Lecanorales, and that Timdalia and Pleopsidium are members of a monophyletic Acarosporaceae. Pycnora, Candelariaceae and Acarosporaceae form a monophyletic group. Umbilicariaceae, Hypocenomyce scalaris, H. friesii, Ophioparmaceae, Boreoplaca, Elixia and Fuscidea form either a basal paraphyletic assemblage in Lecanoromycetes, or a monophyletic group which is the sister-group to Lecanorales and the rest of Lecanoromycetes (excluding Acarosporaceae). The Acarosporaceae forms a group with Pycnora and Candelariaceae, which may be outside the Lecanoromycetes. Chaetothyriales, Verrucariales, Eurotiales, Lichinales and Mycocaliciales form a monophyletic group, but with low support. We briefly discuss incongruence between datasets from different genetic markers, comparing the differences between the separate parsimony analyses, where the ILD test indicated a very significant incongruence. The phylogenetic significance of ascus-types that have influenced most recent Ascomycota classifications heavily is also discussed, and we finally point out risks with formalizing classifications too early.