During a recent expedition of the Eurasian Dry Grassland Group in the steppes of southern Ukraine, we discovered on sand dunes a new sterile crustose aspicilioid lichen with rhizomorphs. It is described here as new to science under the name Circinaria ucrainica (Megasporaceae). The new combination Circinaria reptans (Looman) Khodos. & Darmostuk is also proposed. Circinaria ucrainica is characterized by small grey areoles with a net of dark grey to brownish spicate prothalline tips and pale rhizomorphs. According to the phylogenetic analysis, the new species is closely related to the terricolous Circinaria reptans, but the latter has thicker rhizomorphs of 200–400 μm diameter, finely developed areoles and lacks spicate prothalline tips. Furthermore, we discuss the differences between the new species and other morphologically similar species with rhizomorphs, such as Aspicilia spicata, Circinaria crespiana and C. reptans. The ecological characters of soil and vegetation, including vascular plants, bryophytes and lichens, are provided for the habitat of C. ucrainica.

The new genus Imsharria is proposed for a crustose species found on or near mountain summits on the Falkland Islands. It is separated from other genera of Lecideaceae by a combination of Porpidia-type asci, halonate ascospores, immersed apothecia and a hyaline hypothecium, and forms a distinct branch in the phylogenetic analysis using the markers nrITS and mtSSU. The single species, I. orangei, is characterized by its innate apothecia with a brown disc and a thallus containing norstictic acid and an amyloid (I+ violet) medulla. In addition, Porpidia imshaugii is described for a species from the Falkland Islands resembling P. skottsbergiana but with larger ascospores, and Porpidia navarina is shown to belong in the genus Poeltiaria, with the new combination Poeltiaria navarina being made. A key to the Lecideaceae on the Falkland Islands is provided.

The foliicolous lichen Gallaicolichen pacificus exhibits unique goniocystangia-like structures named peltidiangia and peltidia. Its taxonomic classification within the Ascomycota has been unclear due to the absence of ascomata and lack of molecular data. Here we clarify the phylogenetic affinities of Gallaicolichen pacificus by analyzing mitochondrial small subunit ribosomal RNA (mtSSU) sequences obtained from specimens collected in New Caledonia. Ascomata and ascospores of G. pacificus, previously unknown, are described and illustrated for the first time. The results from the molecular and morphological analyses clearly indicate that Gallaicolichen pacificus belongs to the Porinaceae and is closely related to Porina guianensis. This is a remarkable extension of the already known, wide morphological diversity of thalli and diaspores produced within this family.

Twelve new lichen species are described in the family Arthoniaceae. All are sterile white crusts growing on overhanging trees (and one on living palm fronds) in ten different states in tropical Brazil. In the tropics, sterile crusts so far have been mostly disregarded. They are all characterized by their chemistry and morphology, often including pseudoisidia or soredia, but their phylogenetic relationships have been investigated with sequencing. The following species are described: Arthonia farinosorediata, with shallow soralia and without secondary metabolites; Crypthonia irregularis, with irregular isidia, confluentic acid and sometimes 2ʹ-O-methylperlatolic acid; Crypthonia pseudisidiata, with soft pseudoisidia and without secondary metabolites; Crypthonia stromatica, with sterile stromata and confluentic acid; Cryptophaea constrictopseudisidiata with pseudoisidia, lichexanthone and confluentic acid; Cryptophaea lichexanthopseudisidiata with pseudoisidia and lichexanthone; Cryptophaea lichexanthosorediata with soredia, lichexanthone and divaricatic acid; Cryptothecia lecanorosorediata with soredia and lecanoric acid; Glomerulophoron confluentisorediatum with soredia, confluentic and 2ʹ-O-methylperlatolic acids; Herpothallon psorpseudisidiatum on living palm fronds with a strongly attached thallus, long pseudoisidia and psoromic acid; Myriostigma minisorediatum with soredia and 2ʹ-O-methylperlatolic acid; Pachnolepia longipseudisidiata with long pseudoisidia, and a thallus containing lichexanthone, confluentic acid and 2ʹ-O-methylperlatolic acid.

The production of anthraquinones is a major characteristic of most species in the Teloschistaceae. Other secondary metabolites are quite rare in this family, but some species are known to produce depsides, depsidones, xanthones and usnic acid. A new monotypic genus, Neoplaca, with a new species N. mirabilis, is described from the subfamily Caloplacoideae of the family Teloschistaceae, lacking anthraquinones but containing the naphthopyrans simonyellin and consimonyellin. This is the first time this class of organic compounds has been found in the family Teloschistaceae and the second in the order Teloschistales, where simonyellin has been detected in Brigantiaeaceae. Simonyellin and consimonyellin have also previously been reported in the family Roccellaceae. Neoplaca mirabilis is currently known from the two nearby localities in Yakutia, Russia, where it is common and grows on base-rich soil on exposed south-facing siliceous outcrops. The thallus consists of scattered whitish to greyish, or rarely with pale yellow tinge, squamules 1–4.5 mm diam. and 0.3–1 mm thick with citrine to orange-yellow blastidia produced from their margin; apothecia and pycnidia are unknown. In addition to naphthopyrans, N. mirabilis contains an unidentified brown pigment similar in some features to melanin. The new species is also interesting in that the pigments are apparently located inside the cells of the cortex, not on their surface, where anthraquinones are found in Teloschistaceae.

A first integrative survey of the genus Usnea in the southern Philippines, taking into account morphological, anatomical, chemical and molecular characters, resulted in the recognition of 20 taxa, including three species new to science: Usnea angulata Ach., U. baileyi (Stirt.) Zahlbr., U. bismolliuscula Zahlbr., U. brasiliensis (Zahlbr.) Motyka, U. confusa Asah., U. croceorubescens Stirt., U. dasaea Stirt., U. himalayana C. Bab., U. krogiana P. Clerc, U. longissima Ach., U. nidifica Taylor, U. norsticornuta A. Gerlach & P. Clerc sp. nov. (characterized by a moderately thick cortex and by the presence of norstictic acid), U. paleograndisora A. Gerlach & P. Clerc sp. nov. (characterized by an orange subcortical pigmentation in the medulla, with enlarging soralia and a moderately thick and shiny cortex), U. pectinata Taylor, U. pygmoidea (Asahina) Y. Ohmura, U. rubicunda Stirt., U. rubrotincta (Stirt.) Zahlbr., U. spinulifera (Vain.) Motyka, U. subscabrosa Motyka and U. yoshihitoi P. Clerc & A. Gerlach sp. nov. (characterized by a lax medulla with non-conglutinated hyphae). Usnea krogiana is a new record for Asia; Usnea brasiliensis, Usnea confusa and U. croceorubescens are new records for the Philippines. This is the first phylogenetic study to include DNA sequences of Usnea from the Philippines. Molecular data from the ITS rDNA (76 newly generated sequences) are presented for most taxa except for U. himalayana, U. longissima and U. subscabrosa. At least six further taxa remain unidentified, awaiting the collection of additional specimens.

In recent years, the genus Bryoria (Parmeliaceae, Lecanoromycetes) has been the subject of considerable phylogenetic scrutiny. Here we used information on six gene regions, three nuclear protein-coding markers (Mcm7, GAPDH and Tsr1), two nuclear ribosomal markers (ITS and IGS) and a partial mitochondrial small subunit (mtSSU), to examine infrageneric relationships in the genus and to assess species delimitation in the Bryoria bicolor/B. tenuis group in section Divaricatae. For this purpose, phylogenetic analyses and several of the available algorithms for species delimitation (ASAP, GMYC single, GMYC multiple and bPTP) were employed. We also estimated divergence times for the genus using *BEAST. Our phylogenetic analyses based on the combined data set of six gene loci support the monophyly of sections Americanae, Divaricatae and Implexae, while section Bryoria is polyphyletic and groups in two clades. Species from Bryoria clade 1 are placed in an emended section Americanae. Our study reveals that section Divaricatae is young (c. 5 My) and is undergoing diversification, especially in South-East Asia and western North America. Separate phylogenetic analyses of section Divaricatae using ITS produced a topology congruent with the current species concepts. However, the remaining gene regions produced poorly resolved phylogenetic trees and the different species delimitation methods also generated highly inconsistent results, congruent with other studies that highlight the difficulty of species delimitation in groups with recent and rapid radiation. Based on our results, we describe the new species B. ahtiana sp. nov., characterized by its bicolorous, caespitose, widely divergent thallus, conspicuously thickening main stems, well-developed secondary branches, and rather sparse third-order branchlets. Another new lineage, referred to here as B. tenuis s. lat., is restricted to western North America and may represent a new species recently diverged from B. tenuis s. str., though further work is needed.

An increasing number of studies are describing the diversity of lichen phycobionts, which is leading to a better understanding of how lichen communities are assembled at different taxonomic, evolutionary and geographical scales. The present study explores the identity and genetic diversity of the microalgal partners of Punctelia borreri and P. subrudecta, two tropical and temperate parmelioid lichen fungi that often grow in temperate and Mediterranean forest ecosystems in Europe. Based on a specimen sampling distributed in two climatically divergent regions in the Iberian Peninsula, we found that these mycobionts are associated with Trebouxia gelatinosa, whose identity was also confirmed by an ultrastructural study of the pyrenoid. The bipartite network analysis indicated that each Punctelia species was associated with a different set of low frequency T. gelatinosa infraspecific lineages, whereas the two most abundant phycobiont lineages were shared between both mycobionts. Based on the current sampling, these two algal lineages occur exclusively in one of the two studied regions, which might point towards climate-driven, fine-tuned fungal-algal interactions. Finally, we documented visible symptoms of injury on the thalli in areas likely to have been impacted by air pollution.

Species of lichen-forming fungi (LFF) display an array of geographical distribution patterns. Among the broadly distributed lichen-forming fungal species, the degree of reproductive isolation and genetic substructure among populations varies widely, in some cases masking unrecognized diversity or meaningful biogeographical patterns. Lecidea atrobrunnea (Raymond ex Lam. & DC.) Schaer. s. lat. (Lecideaceae) is a widespread species complex that has been studied for over two centuries since its initial description. The diversity of the L. atrobrunnea group is highest in western North America, where a dizzying array of morphologies and chemistry can occur at local scales. Here we investigate whether the assumed cosmopolitan distribution of L. atrobrunnea s. lat. is an artifact of taxonomic limitations and masks biogeographical patterns in this species complex. To address these questions, we compiled sequence data from the standard fungal barcoding marker (ITS) for over 100 specimens within this complex, in addition to genome-scale data from a subset of these representing over 1600 single-copy nuclear genes spanning over 3 Mb of the genome. Our study corroborates the perspective that the morphologically and chemically variable Lecidea atrobrunnea group reflects a complex of distinct species-level lineages, with 42–83 candidate species inferred from the ITS region and high levels of diversity inferred from a subset of specimens using genome-scale data. However, both phenotype- and molecular-based species boundaries remained unsettled, with the most common nominal taxa recovered as highly polyphyletic and with conflict among different molecular species delimitation approaches. Our study also highlights the potential for geographically restricted species, with fascinating biogeographical patterns, challenging, in part, the assumed cosmopolitan distribution of L. atrobrunnea s. lat. This study provides valuable direction for future research that will be crucial in understanding diversification and establishing a robust taxonomy for this well-known species complex.

Lecanora caledonica is described as new to science. Molecular analyses show that it belongs to the L. intumescens group. It is also rather similar in appearance to L. intumescens, but differs mainly chemically in containing only atranorin and an unknown UV+ ice blue substance. There are also anatomical and morphological differences to the other species of the group. The new species has a pronounced oceanic distribution and is so far known only from western Norway and Scotland.

This study re-examined the status of species of Diorygma Eshw. known from the Western Ghats using an integrative taxonomy approach that includes morphological and chemical data, as well as multigene phylogenetic analyses. Prior to this work, the two species D. karnatakense and D. dandeliense were distinguished primarily on lirellae morphology (branching pattern) and the number of ascospores per ascus. Our study of the morphology, chemistry and molecular phylogeny (mtSSU, LSU and RPB2) of freshly collected samples and re-examination of type material suggests that both names should be synonymized. Consequently, D. karnatakense is accepted as the correct name, with D. dandeliense as a newly proposed synonym. Phylogenetically, D. karnatakense is allied to D. antillarum and D. hieroglyphicum.

Three new species of Arthoniales are described from Cape Verde: Ingaderia dendritica, with ascomata formed of richly branched-dendroid lirellae and containing erythrin; Sparria caboverdensis, with small stroma-like ascomata and ascospores with 3–7 transverse septa; and Syncesia miesii, with an I− thallus, a tomentose hymenial disc, and a chemistry with fatty acids only. Phylogenetic analyses using nuLSU and RPB2 sequences reveal the placement of Fulvophyton sorediatum, Llimonaea occulta, L. sorediata and Sparria caboverdensis in the family Opegraphaceae. The genus Llimonaea is recovered as paraphyletic, with L. flexuosa being placed as sister species to a lineage including the genera Ingaderia and Paraingaderia. In consequence, an enlarged concept of the genus Ingaderia is proposed, resulting in the transfer of F. sorediatum, L. flexuosa, L. occulta, L. sorediata and Paraingaderia placodioidea to Ingaderia.

Cladonia luteoalba shows a specific pattern in chemical variability. Its chemotype coincides with that of the associated Cladonia thalli. This has led to the formation of various hypotheses, but its true nature has never been clarified. We collected C. luteoalba in Central Europe and Norway. The chemotypes were detected by TLC and the mycobionts and photobionts were identified by Sanger sequencing of ITS rDNA. Mycobiont cultures were obtained and Illumina metabarcoding of the fungal ITS1 rDNA region was performed targeting minor mycobionts within the thalli. None of the methods supported C. luteoalba as a distinct Cladonia species. In phylogenetic analyses, it was placed in C. straminea and the C. coccifera agg., following the pattern in chemistry. No minor Cladonia were detected by metabarcoding or cultivation. Thus, C. luteoalba remains enigmatic as our data did not support its distinction as a separate Cladonia species.

In this study, we sampled L. pulmonaria thalli from Mt Kilimanjaro and Mt Meru, Tanzania. Across all sampled tree species, a range of 1–35 thalli of L. pulmonaria were counted per trunk (up to 5 m above ground level), with sampling distributed across 13 (c. 1 ha) plots located in the sub-alpine to montane forest altitudinal gradients of Mt Kilimanjaro and Mt Meru. Descriptive analyses were performed to determine the association of L. pulmonaria with particular host trees among the study sites and regions, and linear mixed effects models (LMM) were used to explore relationships with tree-level variables. The analyses showed that most thalli of L. pulmonaria were unevenly distributed among the tree species in the montane and sub-alpine forests of Mt Kilimanjaro and Mt Meru. Host tree characteristics such as trunk circumference, height on trunk, bark texture and trunk shape appeared to have an effect on the local population size of L. pulmonaria and the frequency of occurrence. Also, the results indicated an effect of trunk circumference and tree bark on the development of L. pulmonaria thallus size among the study sites. Furthermore, host tree species, for example, Hypericum revolutum and Rapenea melanophloeos were important habitats for L. pulmonaria on both mountains, whereas Ilex mitis, Bersama abyssinica and Hagenia abyssinica were important only on one mountain. The wider literature on L. pulmonaria ecology is also reviewed and it is therefore recommended that for successful conservation of the threatened L. pulmonaria in tropical montane forests, strategies should consider the type of the forests, together with the host tree species and their size.

Recent studies have demonstrated that species boundaries among the lichen-forming fungi are in need of revision with the discovery of cryptic species in numerous clades, especially in parmelioid lichens. Here we focus on addressing the species boundaries in Canoparmelia texana, a sorediate species with a pantropical distribution that extends into temperate regions. We extracted DNA sequences of the nuclear ribosomal internal transcribed spacer region (ITS), large subunit (nuLSU) and mitochondrial small subunit (mtSSU) from samples mostly collected in Kenya, and analyzed them in a phylogenetic framework. We illustrate that our samples of the species as currently circumscribed do not form a monophyletic group but fall into two distinct clades, with the apotheciate C. nairobiensis nested within. Both of the discovered lineages have a wide distributional range and are common in Kenya, and Parmelia albaniensis C. W. Dodge is resurrected to accommodate one of the clades; consequently a new combination, Canoparmelia albaniensis (C. W. Dodge) Divakar & Kirika comb. nov., is proposed.

This study investigated the molecular, chemical and morphological variation in the Usnea pectinata aggregate using 42 specimens, 22 from Tanzania and 20 from São Tomé and Príncipe. A total of 31 sequences (13 ITS, 13 nuLSU and 5 RPB1) were generated. The results are presented in two phylogenies: first a three-markers ‘backbone’ phylogeny for the U. pectinata aggregate, where six distinct, strongly supported subclades indicate considerable genetic variation in the dataset; and second, an ITS phylogeny with 47 terminals along with a mapping of morphological and chemistry data. Several well-supported monophyletic clades were recovered in both phylogenies and these may well represent separate species in the complex referred to here as the U. pectinata aggregate. Three morphotypes characterized by axis pigmentation and four by branch shape were noted. Six chemotypes were observed.

The widespread species Parmotrema crinitum (Ach.) M. Choisy and Parmotrema perlatum (Huds.) M. Choisy are mainly distinguished by their reproductive strategies. While P. crinitum propagates by isidia, P. perlatum produces soredia. In this study, we aim to evaluate the phylogenetic relationship between both species and to critically examine their species boundaries. To this purpose, 46 samples belonging to P. crinitum and P. perlatum were used in our analysis, including 22 for which we studied the morphology and chemistry, before extracting their DNA. We used 35 sequences of the internal transcribed spacer region of nuclear ribosomal DNA (ITS) of Parmotrema perlatum from Europe and Africa (20 of which were newly generated), and 11 of Parmotrema crinitum from Europe, North America and North Africa (two newly generated). Additionally, 28 sequences of several species from Parmotrema were included in the ITS dataset. The ITS data matrix was analyzed using different approaches, such as traditional phylogeny (maximum likelihood and Bayesian analyses), genetic distances, automatic barcode gap discovery (ABGD) and the coalescent-based method poisson tree processes (PTP), in order to test congruence among results. Our results indicate that all samples referred to P. crinitum and P. perlatum nested in a well-supported monophyletic clade, but phylogenetic relationships among them remain unresolved. Delimitations inferred from PTP, ABGD and genetic distance analyses were comparable and suggested that P. crinitum and P. perlatum belong to the same lineage. Interestingly, two samples of P. perlatum separate in a different monophyletic clade, which is supported as a different lineage by all the analyses.

Ramalina arsenii sp. nov. belongs to the R. pollinaria group and is easily recognized by its ITS barcode and several micro-morphological characters that are diagnostic in a European context: small size, less than 3 cm long; soralia developing on the underside of lobe apices; absence of excavate depressions on the lower side. Its ecological niche (i.e. rock outcrops and especially underhangs of slightly calcareous rocks, at low and mid altitudes) is also unique. Ramalina arsenii is frequent and locally abundant in France (Alps, Cantal) and Switzerland (western Alps), and is also known from Germany and the Spanish side of the Pyrenees.

The new species Aspicilia malvinae is described from the Falkland Islands. It is the first species of Megasporaceae to be discovered on the islands and only the seventh to be reported from South America. It is distinguished from other species of Aspicilia by the unusual secondary metabolite chemistry (hypostictic acid) and molecular sequence data. The collections of the new species support two lichenicolous fungi: Endococcus propinquus s. lat., which is new to the Falkland Islands, and a new species of Sagediopsis with small perithecia and 3-septate ascospores c. 18–20 × 4–5 μm, which is described here as S. epimalvinae. A total of 60 new DNA sequences obtained from species of Megasporaceae (mostly Aspicilia) are also introduced.

Internal cephalodia of Lobaria pulmonaria were examined in two British locations, one in western Scotland (Isle of Skye) and the other in England (Cumbria, Lake District), sites which were predicted to have contrasting levels of fixed nitrogen deposition. Cephalodia were found to occupy a small proportion of the total biomass averaging (<1%) in both areas. Modelled nitrogen deposition in the sites in Cumbria was 3–6 times higher than in the Skye sites but the cephalodium relative biomass was not significantly different. It is suggested that local climatic and topographic effects might have reduced the estimated rate of nitrogen deposition at the former sites.