Gyalolechia fruticum, a new epiphytic species with a Mediterranean-Macaronesian distribution, is described. It differs in molecular data and in ecology from two closely related calcicolous species, G. luteococcinea and G. marmorata, both formerly called Caloplaca subochracea auct. The new species grows on coastal shrubs (rarely on wood), accompanied by species-rich communities of maritime epiphytic lichens. The typical habitat is undisturbed sand dunes, under dry conditions with frequent spells of humid air from the sea. The species is so far known from Greece, Italy, Tunisia, the Canary Islands and probably mainland Spain. We consider this conspicuous lichen an umbrella species of endangered and declining epiphytic communities of ancient shrub vegetation on well-developed sand dunes along Mediterranean coasts affected by touristic overexploitation.

Three twig-growing lichen species belonging to the family Teloschistaceae from southern Patagonia are described as new to science: Marchantiana pyramus sp. nov., with minute apothecia, orange due to dominant content of emodin, M. ramulicola sp. nov., with minute olive apothecia with dominant parietin and Austroplaca thisbe sp. nov., with clear yellow apothecia also with dominant parietin. Marchantiana subpyracea, M. epibrya and M. queenslandica are new combinations for species which, so far, are known only from New Zealand and Australia. Blastenia circumpolaris is shown to be very common in Patagonia and Marchantiana asserigena is documented for the first time from the Southern Hemisphere, viz. the Falkland Islands. The genus Marchantiana is analyzed here using three genes and is shown to be closely related to Yoshimuria; although appearing as paraphyletic, a monophyletic origin cannot be ruled out. Morphology, ecology and distribution support a monophyletic treatment and Marchantiana is therefore treated as such.

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.

Three species of the family Teloschistaceae (lichenized Ascomycota) are described as new to science from Southern and Eastern Siberia and the Far East. Corticolous Caloplaca saviczii belongs to the genus Caloplaca s. str.; it has C. cerina-like apothecia and green to grey-green, crateriform soralia with a white rim. Lendemeriella aureopruinosa is a saxicolous taxon with a thin grey thallus and small apothecia 0.3–0.6 mm in diameter, with a dark orange disc usually bearing epipsamma and often with a grey true exciple containing the pigment Cinereorufa-green. Orientophila infirma is a corticolous species with an endophloeodal thallus and small orange apothecia, 0.2–0.3 mm in diameter, usually with an inconspicuous thalline exciple. All new taxa presumably have a boreal north-eastern distribution in Asia.

The Southern Hemisphere lichen genus Villophora in subfamily Teloschistoideae is analyzed based on DNA sequence data. Six species are described, five of which are new to science: V. darwiniana and V. wallaceana grow on lignum and bark in southern Patagonia and Tierra del Fuego; V. onas and V. patagonica are lichenicolous or saxicolous on rocks in southern Patagonia; V. rimicola is saxicolous in Antarctica. Based on a three-gene DNA analysis, Tayloriellina is shown to be closely related to Villophora, and Tayloriellina microphyllina is established as a new combination. A key is provided to all species of the two genera. Raesaeneniana maulensis is combined into Villophora.

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.

Based on a combined three locus analysis two new genera, Charcotiana and Amundsenia, are proposed in the lichen family Teloschistaceae, subfamily Xanthorioideae. Charcotiana includes the new species C. antarctica, which is known only from continental Antarctica. The bipolar genus Amundsenia includes the new species A. austrocontinentalis, which is also known only from continental Antarctica, and the Arctic species Caloplaca approximata which is here combined into the new genus. The two new genera are phylogenetically distinct, but poor in morphological characters; the new species consist mainly of minute apothecia in cracks of rocks located in the climatically harshest regions of the Antarctic. They are somewhat similar to another continental Antarctic species, Austroplaca frigida, which is described as a new name based on the illegitimate name Caloplaca frigida Søchting. The distribution of the four species is mapped.

A new genus, Catenarina (Teloschistaceae, Ascomycota), with three species is described from the Southern Hemisphere, supported by molecular data. All species contain the secondary metabolite 7-chlorocatenarin, previously unknown in lichens. Catenarinadesolata is a non-littoral, lichenicolous species found on volcanic and soft sedimentary rock at 190–300 m in and near steppes in southernmost Chile and on the subantarctic island, Kerguelen. Catenarina vivasiana grows on maritime rocks and on rock outcrops in lowland Nothofagus forests, but has also been found at altitudes up to c. 580 m on moss and detritus on outcrops in Tierra del Fuego. The Antarctic species Caloplaca iomma is transferred to Catenarina based on chemical data; it grows on rocks near the coast in maritime Antarctica.

For a long time it has been discussed as to whether Melanelixia fuliginosa comprises one or two species: one darker, mainly saxicolous, and one lighter, mainly corticolous. To settle the question, a morphometric and a molecular analysis were carried out and analyzed using a principal component analysis (PCA). The morphometric analysis indicates a differentiation in several characters between material previously recognized as subspecies fuliginosa and glabratula, but also a considerable overlap in some of them. The molecular analysis of the nrITS DNA gene reveals a clear division of the taxa. Specimens belonging to Melanelia fuliginosa fall out in two different clades, which have good bootstrap support, corresponding to the subspecies fuliginosa and glabratula. Accordingly, we propose that the subspecies should be acknowledged as separate species, Melanelixia fuliginosa (Fr. ex Duby) O. Blanco et al. and Melanelixia glabratula (Lamy) Sandler & Arup.

Using ITS nrDNA sequence data, the Caloplaca cerina group (Teloschistaceae) is defined here as a monophyletic, but internally richly branched lineage. The group is also characterized by a combination of morphological and anatomical characters. Its internal lineages are supported by phenotypic characters in addition to ecology and distribution. Within the large C. cerina group, we have found at least 20 phylospecies in the temperate zone of the Northern Hemisphere. Two species complexes do not produce any vegetative diaspores: the polyphyletic, corticolous Caloplaca cerina s. lat. (six separated cryptic or semi-cryptic species) and the monophyletic C. stillicidiorum s. lat. that grows mainly on plant debris, small shrubs and bryophytes and consists of at least four internal lineages. All lineages producing vegetative diaspores (soredia, blastidia, isidia or lobules) are phenotypically characteristic and represent fairly easily distinguishable species: C. chlorina, C. isidiigera, C. monacensis, C. subalpina, C. thracopontica, C. turkuensis and C. ulmorum. Only the North American sorediate C. pinicola possibly represents an aggregate of species. Caloplaca sterilis is described as a new species. A key to the phenotypically distinguishable species is provided.

Lectotypes are designated for C. albolutea, Caloplaca cerina f. coronulata and for C. monacensis. The Australian C. hanneshertelii belongs to this group, but this and other possible species from the Southern Hemisphere are not treated here in detail. Some species traditionally placed in the C. cerina group due to their similar morphology are excluded here on the basis of our phenotype examinations and molecular data. Caloplaca albolutea, C. mydalaea and C. virescens are uncertain taxa and their identities still remain unclear.

Caloplaca phlogina is shown here to have two kinds of soralia, yellow soralia with anthraquinones versus whitish or white-green soralia lacking pigments. Both kinds are present, growing side by side, in some localities in Scandinavia, but yellow soralia appear to be more common. In contrast, the populations from halophilous shrubs on the Black Sea coast have predominantly white soralia, and they were described as a separate species, C. scythica. A single collection from Chile also has white soralia. Molecular data and phenotype examinations convinced us that Scandinavian and Black Sea populations are conspecific. We consider the North European, phenotypically variable population as a source for the Black Sea population which is ecologically and phenotypically more uniform.

A new taxonomy of the Caloplaca citrina group in the Black Sea region is presented. It is based on the nrDNA ITS molecular data, chemistry (anthraquinone contents) and 20 morphological characters. Six species previously known in the region are accepted: Caloplaca arcis, C. calcitrapa, C. dichroa, C. flavocitrina, C. geleverjae, C. limonia. Five new species are described: Caloplaca arcisproxima, C. austrocitrina, C. communis, C. confusa and C. nigromarina. Seven further species, Caloplaca britannica, C. citrina, C. marina, C. maritima, C. microthallina, C. ora and C. phlogina are also treated briefly. Some maritime species known from the Atlantic coast of Europe are absent from the region, and, surprisingly, Caloplaca citrina s. str. could not be confirmed from the study area. A key to the species present in the region is provided, although morphological characters are of very limited value in this group. The variability and taxonomic importance of particular features are discussed. No significant differences in secondary chemistry were observed among the species.

Many examples of convergence and some semi-cryptic species were revealed by molecular data. The term ‘semi-cryptic species’ is introduced here into lichenology for those species which cannot be clearly diagnosed by their morphology, but which are determined by other characters, mainly by their ecology and distribution. We propose to describe formally such species, in spite of difficulties with subsequent morphological identification.

Caloplaca herbidella (Hue) H. Magn. and C. furfuracea H. Magn. are two isidiate, epiphytic species in the large genus Caloplaca. Caloplaca herbidella in a strict sense is normally grey and fertile with thick, somewhat coralloid isidia, but orange, sterile forms with thin isidia also occur. Caloplaca furfuracea is superficially similar morphologically to C. herbidella s. str. but has thinner, more granular isidia and generally a darker grey colour. Doubts have been raised as to whether C. furfuracea should be acknowledged as a proper species or incorporated in C. herbidella. Using morphometric methods and molecular analysis of the nrITS DNA gene we show that C. herbidella and C. furfuracea are two clearly separated species. Furthermore, the mainly sterile, orange form of C. herbidella can be regarded as a separate species that is here described as C. coralliza Arup & Åkelius. All three species are described in detail, including photographs and notes on their ecology. Finally, new distribution maps for Europe show that C. herbidella and C. coralliza are widespread in Europe, but the latter is probably less common than the former. Caloplaca furfuracea is clearly very rare in Europe with only few collections from Switzerland and Sweden, but seems to be more common in North America.

The Caloplaca holocarpa group in the Nordic countries, except Iceland, is defined genetically using the nrlTS DNA gene. The members are analysed with regard to morphology, anatomy, ecology, and chemistry. The results show that C. holocarpa seems to be a very small group, but there are many morphologically similar species outside the group. Within the group several species have been confused, but it is shown that C. holocarpa, C. pyracea, and C. vitellinula are separate taxa. Caloplaca cerinella also belongs to the group whereas C. cerinelloides does not, but is included in the treatment because of its similarity to the former species. Caloplaca lithophila H. Magn. is a synonym of either C. holocarpa or C. vitellinula, most probably of the latter. Many specimens determined to C. holocarpa belong to Caloplaca oasis, but this species is shown to have much more variable morphology and wider ecology and distribution than previously understood. Caloplaca oasis has also been confused with C. polycarpa, which is similar, but morphologically and genetically distinct, even though related. Neither of the two species belong to the C. holocarpa group, but are related to the C. citrina group, not to the C. velana group as usually believed. Other species from northern and central Europe similar to C. holocarpa belong in other groups. The treated species are described and illustrated in colour. Distribution maps are given for the study area. A key to species in northern Europe similar to C. holocarpa is also provided.

Caloplaca fuscorufa H. Magn. is a poorly known species that for a long time was known only from a single locality in Jämtland, northern Sweden, where it was collected in 1910. It has been suggested to be synonymous with C. crenularia (With.) J. R. Laundon, but has also been confused with C. exsecuta (Nyl.) Dalla Torre & Sarnth. We have compared the isotype of C. fuscorufa and material collected in Sweden, Norway and Svalbard, with presumably related species, using morphology, anatomy and chemistry as well as molecular data. The results show that C. fuscorufa is a distinct species, differing from C. crenularia mainly in its somewhat larger spores with wider septa, different colour of the apothecia and a more northern distribution. It differs from C. exsecuta mainly in its chemistry and smaller spores with smaller septa. Caloplaca crenularia is shown to have a more southern distribution in Sweden than previously understood. Chemical data and a molecular analysis based on ITS data show that C. fuscorufa is related to C. crenularia and C. ammiospila, but clearly separated from these species.

Caloplaca sorediella Arup is described as a new species. It is so far known only from extreme maritime situations on seashore rocks in western England, Scotland and Wales.

The Caloplaca citrina group in the Nordic countries, except Iceland, is analysed with regard to morphology, anatomy, ecology, and chemistry. Their genetic relationship is also analysed using the ITS ribosomal DNA gene. The results show that there are at least five species within what has been called C. citrina, of which four are closely related to one another and to several non-sorediate species. Three of these, C. citrina, C. flavocitrina and C. arcis have previously been recognized at specific or varietal level some time during the last two centuries, whereas the fourth species, C. dichroa, is described as new. The fifth species, C. phlogina, is not related to the other species but shows a close relationship to the Xanthoria candelaria group. The species are described and illustrated in colour. Distribution maps are given for the study area and a key to sorediate, yellow to orange species occurring in the Nordic countries, except Iceland, is also provided.

A molecular phylogeny of the Lecanora rupicola group is presented, based on ITS sequence analyses. The study includes saxicolous and corticolous members of the Lecanora rupicola group as well as other Lecanora species with pruinose apothecia. A phylogenetic hypothesis for species in Lecanora s. lat. and various other genera in Lecanoraceae, based on an alignment-free distance estimation technique, shows that the Lecanora rupicola group forms a monophyletic clade within Lecanoraceae. Affinities to the core group of Lecanora are not well supported, likewise the monophyly of Lecanora s. str. with other species groups in Lecanora, such as the lobate taxa (and Rhizoplaca) is not supported. A more detailed analysis involving Lecanora species with pruinose apothecial discs was carried out with model-based Bayesian Markov chain Monte Carlo (B/MCMC) tree sampling. The results suggest the monophyly of the Lecanora species that are characterized by the presence of chromones. Corticolous as well as saxicolous species are included. Lepraria flavescens is closely related to the Lecanora swartzii subgroup, and the new name Lecanora rouxii nom. nov. is introduced for that species. Other Lecanora species with pruinose discs are not closely related to the Lecanora rupicola group.

A phylogenetic hypothesis based on nuclear ITS sequence data is presented for the family Physciaceae based on various representatives of foliose and fruticose groups and a number of species selected from the crustose genera Rinodina and Buellia s.l. The analysis supports the monophyly of the Physcia- and the Buellia- groups. This is in agreement with existing morphological evidence, particularly ascus characters. The Physcia group in the analysis includes the genera Anaptychia, Heterodermia, Hyperphyscia, Mobergia, Phaeophyscia, Phaeorrhiza, Physcia, Physconia, Rinodina, and Rinodinella, while the Buellia group includes Amandinea, Buellia and Diploicia. The genera Physcia, Phaeophyscia, Phaeorrhiza and Rinodinella were well supported as monophyletic groups. The support for Physconia is low. Rinodina and Buellia are not supported as monophyletic genera. In agreement with ascus and ascospore characters, Buellia lindingeri is placed within the Rinodina group, close R. lecanorina. The genus Amandinea as currently circumscribed was not supported as a monophyletic group. The analysis confirms results from other lichen families that foliose members have evolved more than once from crustose lichens. Rinodina and Rinodinella species without chemical compounds in their thalli form the sister group to Phaeophyscia, and both groups form a monophyletic assemblage. A more detailed analysis of the Physcia group is presented. Whilst several of the foliose genera were well supported, there is only poor support for traditionally accepted crustose genera. The taxonomic implications of these findings are discussed.