During a study on population genetics of three species of Cladonia using the nuclear ribosomal 18S DNA, two species contained group I intron-like sequences located in positions 788 and 940 with reference to the E. coli 16S rDNA gene. The intron in position 940 was not typical of group I introns and had previously been described only from the Parmeliaceae and Lecanoraceae, but here we report the occurrence of this intron in the Cladoniaceae. The intron in position 788 had characteristics of group I introns and had previously been reported from the Physciaceae. In this paper we provide for the first time a putative RNA fold for the nS788 intron, compare the secondary RNA structure of the Cladonia group I introns (nS788 and nS940) to that of other taxa, and infer a phylogenetic history among 15 members of the Lecanorales based on the evolutionary history of the nS788 group I intron. The RNA fold for nS788 contained two optional hairpins, P2.1 and a potentially newly described hairpin referred to as P5.1. The phylogenetic hypothesis supports the monophyly of the genus Cladonia. It also supports the separation of two large groups in the Physciaceae; the Buellia-group and the Physcia-group.

Nimisia deusta, based on Parmelia enteromorpha var. deusta, is shown to be the correct name for the species currently known as N. fuegiae. Original material collected by J. D. Hooker in 1842, and collections made by Henry Imshaug between 1968 and 1971, have shown that the species is more widely distributed than previously reported, being known throughout the southern tip of South America (Argentina: Isla Grande de Tierra del Fuego, Isla de los Estados; Chile: Cape Horn Islands; Falkland Islands), that it has a uniform secondary metabolite chemistry of fumarprotocetraric acid in the upper medulla (not lacking lichen substances as previously reported), and that it is not uniformly black but has a partly pale brown upper cortex.

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.

A new species of Chaenotheca, C. biesboschii, has been found in the freshwater tidal area of the Biesbosch in the Netherlands, a national park well known for harbouring several rare and threatened mosses and lichens. A phylogenetic analysis of the ITS region revealed some strongly supported infrageneric clades in Chaenotheca which were given informal names, and some were assigned provisional names in anticipation of generic recognition. The analysis also showed that the new species differed in the sequenced region from other European Chaenotheca species. Chaenotheca biesboschii might be mistaken for C. gracillima but, in addition to a considerable difference in the ITS region, it also differs from this species in morphology. It is also similar to C. servitii but again differs in morphology. Chaenotheca biesboschii inhabits decorticated wood in the oldest stages of forest development of abandoned willow coppices. In 2016 and 2017 a fairly large population was found in an area comprising several square kilometres. In the Biesbosch area, extensive woodlands have developed only since the 1950s and therefore C. biesboschii might have been recently established in the area, possibly following climatic warming. The new species is characterized by having an immersed, glaucous green thallus; apothecia 0·9–1·4 mm high; capitulum on the lower side when young with a ring-like thickening covered by a yellow pruina; when mature with a rusty brown pruina on the capitulum and upper part of stalk; spherical spores, 3·5–5·5 µm diam., ornamented by irregular cracks, medium brown; photobiont Stichococcus. A key to the European species of Chaenotheca is provided.

Small clay cubes, fired at different temperatures and mounted with nylon touch and close fastener (Velcro®) on acrylic glass plates, were used in an experimental design to study colonization of artificial substrata by lichens. The cubes were exposed in alpine streams for either 5–7 y at five different sites in the Swiss Alps: Flüelatal (three sites) and Brigels (Canton of Graubünden), and Eggerberg (Canton of Valais). Only a few cubes were lost, except at two sites, where complete plates were lost – due to the strong water current and, probably, trampling by cattle. After 3 y, freshwater lichens had grown at three sites. At the most elevated site, colonization was observed after 4 y; at one site no lichen growth was recorded. The first colonizers of the new substrata were the locally most common species. Freshwater lichens preferred the surfaces of clay cubes fired at lower temperature, whereas exposed pieces of local rocks were less frequently colonized. Improvements in the experimental design are suggested.

Rinodina fuscoisidiata, a muscicolous isidiate species with large isidia and Pachysporaria-type ascospores is described from Venezuela. This species contains an unknown terpene as a major secondary metabolite in addition to traces of atranorin. It is compared with the four known isidiate Rinodina taxa.

This study investigates how anatomical characters can be used to differentiate two morphologically close species, Melanohalea olivacea (L.) O. Blanco et al. and M. septentrionalis (Lynge) O. Blanco et al. Although the two species are morphologically differentiated, mainly based on the position and shape of pseudocyphellae on the lobes, poorly-developed specimens can be difficult to identify based on morphology alone. For example, in Switzerland, both species are at the south-west limit of their distribution range and most specimens are small and not fully developed. In such cases, anatomical characters are particularly useful in separating the two species. Five anatomical characters were studied: spore length and width; hymenium, subhymenium and hypothecium height. A nested ANOVA showed that variation of spore length was 155 times greater between species than between individuals of the same species, itself 5 times higher than within individuals. In a Principal Component Analysis, despite a substantial variation of the anatomical characters within both species, a significant species differentiation appeared distinctly on the first axis (P < 0·001), which accounted for 62·35% of the total variance, and the type specimens nested within each species. Finally, a Discriminant Linear Analysis assigned 100% of the individuals to their species class, the best predictors to discriminate between the two species being subhymenium height and spore length. These characters proved to be powerful in identifying specimens with a poorly-developed morphology and confirmed the presence of M. olivacea in Switzerland.

In a recent phylogenetic analysis of the family Teloschistaceae based on three molecular markers, 31 genera were newly described or resurrected. One of these genera was Parvoplaca, currently including four species in which anthraquinones may be present or absent in the apothecia. We have re-analyzed the genus and propose one new species, P. nigroblastidiata Arup, Halıcı & Vondrák, and one new combination, P. chelyae (Pérez-Vargas) Vondrák, Halıcı & Arup. The new species is known at present from Sweden, Turkey and Alaska. It is characterized by an endophloedal thallus, black blastidia produced in small spots and zeorin-lecanorine apothecia with an orange disc and black thalline margin. It is morphologically similar to Caloplaca turkuensis, but differs in the zeorine-lecanorine apothecia and the thalline margin that is dark grey-black instead of grey.

Wapusk National Park is part of the Hudson Bay Lowlands in Manitoba and covers 11 475 km2. Lichen surveys were initiated in 2002 but none have reported all species incorporating broad habitat types or a baseline on which to make management decisions. The objectives of this study were: 1) to determine species diversity, including species richness and evenness of the lichens present; 2) to explore species distributions; and 3) to compare lichen growth form and substratum relationships among physiographic regions. Fifty-six locations in four habitat types (physiographic regions: open coastal beach ridge, forested coastal beach ridge, boreal transition forest, and peat plateau bog) and three burned locations were visited over nine years and specimens were collected at each location. A total of 276 species and subspecies were collected. One species is new to Canada (Buellia uberior Anzi) and ten species are new to Manitoba. Species diversity, evenness, and richness were highest in the coastal beach ridge. The open coastal beach ridge, boreal transition forest, and peat plateau bogs formed separate clusters in the non-metric multidimensional scaling (NMS) but the forested coastal beach ridge overlapped with the open coastal beach ridge. Unique species in each region may serve as indicators to monitor long-term changes. While the coastal beach ridge facilitates travel along the coast, it also represents the region with the highest need for intervention to conserve species diversity.

While studying the taxonomy of the non-yellow species of Rhizocarpon DC., with hyaline and muriform ascospores, in the Nordic countries (Ihlen 2004), some specimens of Rhizocarpon from the Svalbard archipelago were also examined. Among this material, we discovered six specimens of Rhizocarpon anaperum (Vain.) Vain. that had been labelled “R. obscuratum”. As R. anaperum is not listed in the recent checklist from Svalbard (Elvebakk & Hertel 1996) or, to our knowledge, in any other paper dealing with the lichen flora of Svalbard, it is here reported new to this archipelago.

Acanthothecis salazinica and Diorygma archeri are described from Vietnam. The former is characterized by having a leprose thallus, creamish to whitish, entire, epruinose labia, a slit-like disc, a hyaline to brown, entire proper exciple, warty periphysoids, 8-spored asci, and 28–30-loculate, hyaline, I− ascospores, 70–120×7–14 µm in size. The latter has a greenish grey thallus, a poorly developed, hyaline to pale or brownish proper exciple, 1-spored asci, hyaline, muriform ascospores, and produces protocetraric acid. Acanthothecis corcovadensis, Diorygma erythrellum, D. junghuhnii, D. macgregorii, Platygramme platyloma, Pliariona montagnei and Thecaria quassiicola are recorded for the first time from the country.

The identification of mycocalicioid species continues to be based on morphological and chemical characters, even though molecular data and substratum preferences can provide many important insights into specific problems associated with species delimitation and other taxonomic challenges. Our results reinforce the usefulness of many morphological and chemical characteristics and reveal several new features that can be used for both species delimitation and identification. Given the fact that mycocalicioid species can rarely be distinguished by just a single character, combinations of different chemical and morphological characteristics must be used. Additional characteristics must also be sought, including those that have previously been overlooked or still need to be discovered. As a result of this search, we introduce a new term, pseudohemiamyloid, for a reversible, KOH resistant/enhanced reaction in Lugol's solution.

Examination of Rinodina specimens from the Cape Verde Islands revealed three new species, which are described here: Rinodina capeverdeana Giralt & van den Boom, R. inspersoparietata Giralt & van den Boom and R. polymorphaespora Giralt & van den Boom. Additional information is given for six further species, of which five are new records for the archipelago. Rinodina punctosorediata Aptroot & Sparrius was found to be conspecific with R. stictica Sheard & Tønsberg.

Schaereria dolodes (Nyl. ex Hasse) Schmull & T. Sprib. comb. nov., an epiphytic lichen species known from western North America was originally described as a member of the genus Lecidea sensu lato. However, its morphology is very characteristic of the genus Schaereria Körb. Here, we lectotypify the species and propose its placement in the latter genus. It is also reported as new to Canada from British Columbia.

Graphis tetralocularis C. Bock & Hauck is described as a new species from Rwanda. It is characterized by triseptate, hyaline ascospores 12–15(–17)×5–7·5 μm, a connivent, laterally carbonized exciple and by the presence of atranorin. So far, G. tetralocularis is only known from the type locality in central Africa, where it grows epiphytically on Nuxia floribunda in a dry forest.

Lecanora s. lat. is a genus of crustose, rarely placodioid lichens comprising c. 1000 recognized species and subdivided into several morphology-based groups. Some of these groups have been supported in phylogenetic analyses and segregated as new genera. One of the remaining groups that has not been previously studied by molecular methods in much detail, the L. saligna-group, includes corticolous and lignicolous crustose lichens, usually containing isousnic or usnic acid (or both) as major secondary metabolites. As part of our ongoing project ‘Lecanomics’, a phylogenetic analysis based on two loci was conducted and found the L. saligna-group to be divided into two main clades and several well-supported minor clades. The L. varia clade, chosen as one of the outgroups, emerged within the L. saligna-group. The majority of the clades are characterized by phenotypic differences. However, several well-supported clades share similarities with their sister groups, suggesting that species circumscriptions based solely on phenotypic characters may be too conservative to characterize the true species diversity present within the group. Also, there is evidence for some geographical separation of lineages; for example, most North American individuals, previously known as Lecanora saligna and L. albellula, form two clades separate from their European namesakes and are here preliminarily called ‘Lecanora sp. B’, ‘Lecanora sp. C’ and ‘Lecanora sp. D’. However, L. saligna and L. albellula also appear to occur in North America, and some specimens from the Caucasus and Iran cluster within the North American clades. Lecanora anopta and L. subravida are reported for the first time from Iran.

The genus Graphis sensu Staiger was recently divided into two genera, Graphis s. str. and Allographa. The latter contains mostly species with robust lirellae with a well-developed, often massively carbonized excipulum. With one exception, it also contains all species with a pigmented, yellow to orange pruina on the lirellae. Until now, seven species of Allographa were known with this character, all present in the Neotropics and one also in Africa. Here we describe two further species, both from tropical Asia, thus extending the known distribution of Allographa species with pigmented lirellae to the entire tropics. Allographa kamojangensis Jatnika, Noer & Lücking sp. nov. from Indonesia (Java) was recognized as a new taxon on the social media Facebook site Lichens Connecting People. Detailed studies showed that it deviates from the neotropical A. firferi in the much larger ascospores and the orange, K+ immediately purple-violet pigment, and from A. lutea in the completely carbonized excipulum and the larger ascospores. Allographa jayatilakana Weerakoon, Arachchige & Lücking sp. nov. was discovered in the second author's backyard during a recent inventory of Graphidaceae in Sri Lanka. It differs from A. flavominiata in the much shorter ascospores, from A. firferi in the terminally muriform ascospores, and from A. ochracea in the yellow-orange, K+ yellow then slowly purple-violet pruina. A key is presented to all nine species of Allographa with pigmented lirellae.

Pannaria is shown to include species whose thallus ranges from the almost homoiomerous to the fully differentiated heteromerous state. A new species of Pannaria is described, P. santessonii, with a thallus closely resembling that characteristic of the Collemataceae. Lepidocollema carassense Vainio and Lepidoleptogium montaguei A. L. Sm., the type species of these respective genera, have beenfound to have a similar type of thallus. Further study of the relationship between thesegenera is needed.