As part of a revision of the genus Acanthothecis s. lat. (Graphidaceae) in Brazil, an updated world key to the known species of the genus is presented. From Brazil, the following ten new species are described: A. latispora, with single-spored asci, large, muriform ascospores, and norstictic and stictic acids; A. megalospora, with single-spored asci, very large, transversely septate ascospores, and norstictic and protocetraric acids; A. multiseptata, with 8-spored asci, medium-sized and narrow, transversely multiseptate ascospores, and lacking secondary substances except terpenoids; A. norstictica, with 1–2-spored asci, large, muriform ascospores, and norstictic acid; A. oryzoides, with 8-spored asci, medium-sized, transversely septate ascospores, and norstictic acid; A. rimosa, with 2-spored asci, small to medium-sized, muriform ascospores, and stictic acid; A. roseola, with 1–2-spored asci, large, muriform ascospores, and norstictic, stictic and subnorstictic acids; A. saxicola, with 8-spored asci, small, 3-septate ascospores, and norstictic acid; A. subfarinosa, with 8-spored asci, small, 6–8-septate ascospores, and norstictic acid; and A. submuriformis, with 8-spored asci, small, submuriform ascospores, and lichexanthone. In addition, three further species are formally validated, namely A. bicellulata, A. farinosa and A. subabaphoides, and the new combination A. bicellularis is proposed, based on Acanthotrema bicellularis.

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.

Detailed morphological investigations and phylogenetic analyses of the ITS/5.8S nrDNA, mtLSU and RPB2 of the Umbilicaria crustulosa–U. spodochroa species complex reveal Umbilicaria hirsuta var. meizospora Harm. to be a separate species. The lectotype has been designated in ANGUC and a new combination Umbilicaria meizospora (Harm.) D. M. Masson & Davydov is proposed. Umbilicaria crustulosa var. badiofusca was recognized as the heterotypic synonym of U. meizospora and the lectotype was designated based on Frey's collection preserved in G. We provide a full description of U. meizospora and outline its distribution and ecology. The species is newly reported from Austria.

Twenty-eight species of Verrucariaceae are reported from Nepal. One genus and nine species are described as new: Nesothele gen. nov., sister to Staurothele s. lat., with a crustose to squamulose thallus, hymenial algae and 4–8 colourless muriform ascospores per ascus; Nesothele glebulosa sp. nov., resembling N. rugulosa but with smaller perithecia; Thelidium uvidulum sp. nov., producing a thin thallus with soralia, prominent perithecia, and 1-septate ascospores; Verrucaria antepotens sp. nov., having a well-developed thallus with dark-sided areoles, immersed perithecia, and small ascospores 12.5–16.5 μm long; V. lactea sp. nov., resembling V. praetermissa but with larger ascospores and a strongly deviating ITS sequence; V. parvipeltata sp. nov., with brown, basally constricted areoles on an extensive dark prothallus; V. senta sp. nov., with a brown cracked thallus and prominent naked perithecia; Willeya eminens sp. nov., with prominent perithecia, and differing from W. protrudens in its ITS sequence; W. irrigata sp. nov. with a thallus cracked into dark-sided areoles, and relatively large ascospores 28.5–40 μm long; W. nepalensis sp. nov. with a cracked thallus, immersed perithecia and a distinctive ITS sequence. Three species complexes might contain new taxa, but wider geographical sampling is necessary before delimiting species: Thelidium minutulum, Verrucaria elaeomelaena and V. hydrophila. Five new combinations are made: Willeya honghensis comb. nov. (for Staurothele honghensis), Nesothele globosa comb. nov. (for Endocarpon globosum), N. hymenogonia comb. nov. (for Staurothele hymenogonia), N. rugulosa comb. nov. (for Staurothele rugulosa) and N. succedens comb. nov. (for Staurothele succedens). Four species are unidentified.

Harpidium longisporum is proposed as a new species. It is characterized by an areolate, mainly black thallus with trebouxioid algae, K+ blue-purple pigmented parts, pycnoascocarps forming aspicilioid apothecia, with moniliform paraphyses, unitunicate-rostrate, thick-walled asci and long sigmoid, lunate to falcate or irregularly curved and twisted ascospores, growing on steps of a vertical, intermittently moist, gneiss rock face. The genus Harpidium now comprises four species worldwide and, based on the selected specimens, a genus synopsis, a comparative table and a key to the species are included.

Five Graphis species are reported as new to Europe from the Mata Nacional do Buçaco, a region in Portugal where graphidoid Graphidaceae are abundant and diverse. The following species were identified: Graphis dendrogramma, G. duplicata, G. gonimica, G. librata and G. pyrrhocheiloides. An updated key is given to the Graphis species known from Europe. All those newly reported were identified with names corresponding to tropical species.

A new species in the genus Phaeophyscia is described from Azad Jammu and Kashmir, Pakistan, supported by nrITS sequences, morphology and chemistry. The taxon is characterized by a green to greyish green thallus, usually narrow (0.5–2 mm), flat to convex lobes with abundant marginal soralia, black, dense small rhizines, small Physcia-type ascospores 18–22 × 8–10 μm and an absence of pycnidia. Differences from related species are discussed.

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.

Tropical mountain forests are hotspots of biodiversity that are widely threatened by human population pressure and climate change. However, the cryptogamic species richness of many tropical mountain regions is insufficiently known, the poorly understood biodiversity of tropical African lichens being a prime example. To study the diversity of the genus Peltigera (Ascomycota, Lecanoromycetes) in East Africa, we studied lichens in a wide range of habitats on the slopes of Mt Kilimanjaro in Tanzania. Ranging from savannah to alpine heath vegetation and from natural forests to agricultural environments, 13 habitat types were sampled for lichens, which were then identified based on the nuITS genetic marker and morphology. We found eight Peltigera species on the slopes of Mt Kilimanjaro, including P. alkalicola sp. nov., P. dolichorhiza, P. polydactyloides, P. praetextata, P. rufescentiformis, P. seneca, P. sorediifera and P. ulcerata. Peltigera is most common and species-rich in the subalpine Erica forest zone, and four of the eight detected species were present only in the subalpine and alpine vegetation zones. Peltigera alkalicola was identified as a previously undescribed species, growing on trachybasaltic lava in the subalpine and alpine zones of Mt Kilimanjaro. The species resembles P. lepidophora but differs by possessing smaller thalli and peltate isidia that are distinctly dark on the lighter, tomentose lamina. Based on data from the NCBI GenBank, P. alkalicola probably also occurs in Alaska (USA) and Ningxia (China). This suggests that even though the species might generally be rare, it may have a global distribution in extreme mountain environments. For the first time, we report P. sorediifera from Tanzania and P. seneca from Africa.

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.

The species of Heterodermia in Brazil have been revised based on literature reports, public databases and examination of 500 recent specimens from 15 states. So far, 43 species have been reported in the literature, two of which are not accepted here. We report 10 additional species from Brazil and describe 15 new to science, mostly from the Atlantic rainforest biome, raising the total number to 68, including two still undescribed species from Santa Catarina State. A key to all accepted species is given, keying out more species than represented in any previously published key of the genus. Based on new phylogenetic work, we do not accept the split genera that were recently proposed. We do informally recognize an additional group, the H. dactyliza-group. The following species are described as new: Heterodermia amphilacinulata M. F. N. Martins & M. P. Marcelli, H. caneziae M. F. Souza & Aptroot, H. delicatula M. P. Marcelli & M. F. N. Martins, H. dissecticodiademata M. F. Souza & Aptroot, H. dissecticoflabellata M. F. Souza & Aptroot, H. flavodactyliza M. F. Souza & Aptroot, H. flavulifera M. F. Souza & Aptroot, H. labiata M. P. Marcelli & M. F. N. Martins, H. macrosoraliata M. P. Marcelli & M. F. N. Martins, H. minor M. F. Souza & Aptroot, H. neocrocea M. F. Souza & Aptroot, H. nigromarginata M. F. Souza & Aptroot, H. phyllalbicans M. F. Souza & Aptroot, H. spielmannii M. F. Souza & Aptroot and H. sublinearis M. P. Marcelli & M. F. N. Martins. The following new combinations are also proposed: Heterodermia africana (Kurok.) M. F. Souza & Aptroot and H. borphyllidiata (Kalb & Meesim) M. F. Souza & Aptroot. Dissectic acid was found in species belonging to three different groups and was not restricted to (and characteristic of) one subgroup, as previously reported.

This study describes a new species of Hypotrachyna subgenus Parmelinopsis from the south-eastern Cerrado (Brazilian savannah), a biodiversity hotspot. The species is especially common in open vegetation, including urban environments. Hypotrachyna neohorrescens sp. nov. is morphologically and chemically similar to H. horrescens. Nevertheless, phylogenetic analyses of the nuITS and mtSSU regions revealed that H. neohorrescens is a distinct species and closely related to the North American H. mcmulliniana, differing by the size of the laciniae and ascospores.

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.

According to morphological and molecular data, a new species of Lecidea s. str., Lecidea glacierensis, is described from Xinjiang Province, China. It is distinctive due to its well-developed, regularly areolate to bullate thallus, and its habitat on calciferous rocks. This species was collected mostly in the area of Tianshan No.1 Glacier, which is located at an elevation of 3454 m and c. 118 km south-west of Urumqi and is considered to be one of the most important dryland glacier areas in Asia. An illustration and detailed description of the taxon are provided.

Normandina acroglypta, as recently circumbscribed, is shown to comprise two species: N. acroglypta s. str. with subsquamulose marginal areoles, two unidentified terpenoids by thin-layer chromatography, and growing over rock; and N. chlorococca, with convex marginal areoles, zeorin or no substances detected by thin-layer chromatography, and growing over bark. Normandina dictyospora is newly described from the Falkland Islands and is characterized by relatively large, submuriform ascospores, and no substances detected.

Additions and corrections are provided for the South African species of Graphidaceae tribe Graphideae with hyaline ascospores. Allographa oldayana I. Medeiros sp. nov. is described as new to science based on morphological, chemical and molecular data. The new species is characterized by lirellae with striate labia and a complete thalline margin, a completely carbonized excipulum, large, muriform ascospores, and the presence of hirtifructic acid. Allographa consanguinea (Müll. Arg.) Lücking, A. leptospora (Vain.) Lücking & Kalb, Diorygma aff. minisporum Kalb et al., Graphis crebra Vain., Gr. dupaxana Vain., Gr. furcata Fée, Gr. handelii Zahlbr., Gr. longula Kremp., Gr. pinicola Zahlbr., Gr. proserpens Vain, Gr. subhiascens (Müll. Arg.) Lücking and Platythecium sp. are reported as new records for South Africa. Allographa striatula (Ach.) Lücking & Kalb, Graphis analoga Nyl. and Gr. scripta (L.) Ach. are shown to be misapplied names that should be removed from the South African checklist. The new combination Mangoldia bylii (Vain.) I. Medeiros comb. nov. (bas. Graphis bylii Vain) is made; this represents an earlier name for M. atronitens (A. W. Archer) Lücking et al. Taxonomic notes are provided for Graphis bylii var. lividula Vain. and Gr. denudans Vain., species that are known only from their South African holotypes. Phylogenetic analyses that include new DNA sequence data from the nrLSU, mtSSU and RPB2 loci confirm the generic placements of several species for which molecular data were lacking: Allographa consanguinea, Glyphis atrofusca (Müll. Arg.) Lücking, Graphis crebra and Gr. subhiascens.

We provide an updated, worldwide key to species of the genus Carbacanthographis, which is characterized by lirellate ascomata, a carbonized excipulum, warty periphysoids, and mostly non-amyloid ascospores. New collections and revision of herbarium material revealed 17 species new to science: Carbacanthographis acanthoamicta, with a thinly corticate thallus, a completely carbonized excipulum, apically warty paraphyses, small and (sub-)muriform ascospores, and salazinic acid; C. acanthoparaphysata, with a completely carbonized excipulum, apically warty paraphyses, small and submuriform, amyloid ascospores, and protocetraric acid; C. aggregata, with aggregated lirellae, a completely carbonized excipulum, small and submuriform ascospores, and salazinic acid; C. amazonica, with a completely carbonized excipulum, small and transversely septate ascospores, and stictic acid; C. aptrootii, with a completely carbonized excipulum, apically warty paraphyses, small to medium-sized and transversely septate, amyloid ascospores, and norstictic acid; C. brasiliensis, with a completely carbonized excipulum, apically warty paraphyses, medium-sized and transversely septate, amyloid ascospores, and no substances; C. chionophoroides, with a completely carbonized excipulum, small and transversely septate ascospores, and protocetraric acid; C. halei, with a corticate thallus, a completely carbonized excipulum, small and transversely septate ascospores, and stictic acid; C. latispora, with a completely carbonized excipulum, very large and transversely septate ascospores, and stictic acid; C. megalospora, with a corticate thallus, a completely carbonized excipulum, very large muriform ascospores, and stictic acid; C. multiseptata, with a completely carbonized excipulum, very large and transversely septate ascospores, and protocetraric acid; C. novoguineensis, with a completely carbonized excipulum, small and submuriform ascospores, and salazinic acid; C. pseudorustica, with a corticate thallus, a completely carbonized excipulum, medium-sized and transversely septate, amyloid ascospores, and stictic acid; C. salazinicoides, with a corticate thallus, a completely carbonized excipulum, medium-sized and muriform ascospores, and salazinic acid; C. sipmaniana, with a completely carbonized excipulum, apically warty paraphyses, small and transversely septate, weakly amyloid ascospores, and norstictic acid; C. spongiosa, with a completely carbonized excipulum, inspersed hymenium, small, transversely septate ascospores, and stictic acid; and C. subchionophora, with a completely carbonized excipulum, small and transversely septate ascospores, and protocetraric acid. New molecular data confirm the position of C. megalospora in the genus. In addition, we propose one new combination, Carbacanthographis nematoides. The known world distribution of four species is expanded: C. amicta is reported from Papua New Guinea; C. induta from Thailand; C. marcescens from French Guyana and Papua New Guinea; and C. stictica from Colombia, French Guyana, Venezuela and Suriname. For all species, short descriptions and distribution notes are given, and most species are illustrated.

Two species of lichenicolous fungi are described as new to science: Lichenotubeufia etayoi Zhurb. (on Trachyderma), with light orange perithecia up to 360 μm diam., non-fasciculate excipular hairs, and 10–13-septate ascospores, 110–162 × 3–5 μm; and L. tibellii Zhurb. (on Coccocarpia), with light orange perithecia up to 275 μm diam., non-fasciculate excipular hairs, and 5–12-septate ascospores, 50–100 × 3–4.5 μm. An updated key to the species of Lichenotubeufia is provided.

Trees have a crucial importance in the functioning of ecosystems on Earth. They are among the largest and longest-living taxa and provide habitat and shelter to numerous species belonging to diverse groups of organisms. Relict trees are of particular interest through their history of survival and adaptation, and because they potentially shelter rare or threatened organisms today. We investigated for the first time the diversity and distribution of epiphytic lichens and bryophytes found on the Cretan (Greek) endemic and relict phorophyte Zelkova abelicea (Ulmaceae). Our results showed that Z. abelicea hosts a high number of epiphytes. The Levka Ori mountain range in western Crete seems to be a hot spot for epiphytic lichens on Z. abelicea. Bryophytes had the highest diversity on Mt Kedros in central Crete but were absent from several other sites. Moreover, 17% of the studied lichens were recorded for the first time for Crete and 5% have never been recorded for Greece. Geographical position and browsing intensity seem to be important factors influencing the epiphytic community encountered. Tree morphology (dwarfed or arborescent) was also significant in influencing community composition although it was not possible to dissociate this factor from the effect of topography. Dwarfed individuals were found to have as much epiphytic diversity as arborescent trees. Ecological indicator values showed that high epiphytic diversity was found in some sites despite signs of eutrophication and disturbance due to pastoral activities and suggest the co-occurrence of both disturbance tolerant and sensitive species. Our results show how little is known about the biodiversity of Cretan phorophytes and highlights the need for further research on the topic.