Detailed morphological and anatomical studies informed by molecular inferences with mtSSU as a marker revealed two new species of Micarea in Western Europe, both belonging to the core group of the genus, namely the M. prasina group: M. herbarum from the Netherlands and Poland and M. meridionalis from Portugal and Italy. Micarea herbarum looks like a small or depauperate M. denigrata but clearly differs by the lack of gyrophoric acid, while M. meridionalis is distinguished by its granular thallus and the production of micareic acid.

The lichen genus Ochrolechia found in China is revised. Twenty taxa are accepted in the genus, including four described as new to science: Ochrolechia alticola, differing from O. mexicana by the larger ascospores and the absence of lichexanthone, and from O. africana by the C+ red reaction of the apothecial margin cortex, the absence of 5-O-methylhiascic acid, and its alpine habitat; O. lijiangensis, differing from O. longispora by the larger apothecia and smaller ascospores, and by the presence of an additional undetermined fatty acid; O. longispora, differing from O. trochophora by the larger ascospores and the presence of two fatty acids; and O. rugomarginata, differing from O. pallescens in the minutely verruculose margins of the mature apothecia, the absence of variolaric acid and the C+ red thallus cortex, and from O. trochophora var. trochophora by the presence of alectoronic acid in the apothecial medulla, the coarsely pruinose disc and a preference for the bark of coniferous trees. Four new taxa are reported for China: Ochrolechia arborea, O. mahluensis, O. szatalaënsis and O. trochophora var. pruinirosella. An identification key to all taxa in the genus known from China is provided.

Lecanora inaurata, a corticolous member of the L. subfusca group, is described as new to science. This species is characterized by typically epruinose, reddish brown apothecial discs, a chlarotera-type epihymenium, pulicaris-type amphithecium, and chloroatranorin and zeorin as major constituents, often with accessory calycin in the thalline margins of the apothecia, imparting a distinctive yellow halo appearance when present in sufficient concentrations. Lecanora inaurata occurs in open hardwood-dominated woodlands of the Edwards Plateau and grasslands of the southern Great Plains in Oklahoma and Texas.

Amandinea lobarica, a new corticolous lichen species, is described from high elevations in Guatemala. It is characterized by a thin, granulose, brownish thallus containing lobaric acid, small, convex lecideine apothecia, filiform conidia and large, narrowly ellipsoid ascospores with roughly ornamented walls. The new species is compared with other Buellia s. lat. taxa that possess rather large and strongly ornamented ascospores, such as Buellia hypothallina, here placed in synonymy with Gassicurtia vaccinii, Amandinea leucomela, A. mediospora, A. megaspora, A. subduplicata and five very closely related taxa treated here as belonging to the Amandinea incrustans group. Two tables summarizing the main differences between these species and a key are provided. New data on the chemistry of A. leucomela and a new record of A. montana for Guatemala are also included.

Detailed anatomical and chemical studies conducted on recent collections made in almost all suitable habitats on Réunion, a small remote tropical island in the Indian Ocean, yielded a surprising diversity in the widespread lichen genus Micarea (Pilocarpaceae, Lecanorales). Twenty-one species are recognized, including 13 described here as new to science. They are: Micarea alectorialica, M. bebourensis, M. borbonica, M. boryana, M. cilaoensis, M. hyalinoxanthonica, M. isidiosa, M. melanoprasina, M. pseudocoppinsii, M. pseudolignaria, M. sublithinella, M. takamakae and M. tenuispora. Notes on local ecology and important biogeographical features are also given and a key to the species is provided. Isidiiform areolae are reported for the first time in the genus (M. isidiosa and M. tenuispora), as well as the production of protolichesterinic and confluentic acids (M. sublithinella and M. takamakae, respectively). Two groups within the genus are species-rich on the island: the M. peliocarpa group with possibly 5 species, including 3 new to science, and the M. prasina group with 4 species, including 2 new to science. Micarea levicula is reported here for the first time since its description, and the status of the material that can be referred to M. micrococca s. lat. needs further study.

The new species Miriquidica invadens Hafellner, Obermayer & Tretiach is described and reported from Austria, Bulgaria, Italy, Switzerland, France and Spain. From a morphological point of view the species belongs to the M. griseoatra group, in which it is, so far, the only constantly lichenicolous taxon. Chemically it is characterized by the regular presence of miriquidic acid, stictic acid, and constictic acid (in variable amounts). It starts its ontogenetic life cycle as an obligate youth parasite on Sporastatia, usually S. polyspora.

Morpho-anatomical treatments of other species of the Miriquidica griseoatra group occurring in Europe, based on the examination of type material, are also presented. According to the characters exhibited by the lectotype of Lecidea contigua var. griseoatra Flot., M. griseoatra (Flot.) Hertel & Rambold is the correct name for a montane species with subdivided areoles and immersed, laterally adnate apothecia with a pigmented hypothecium. Specimens exhibiting this set of characters were usually named M. obnubila auct. According to the characters observed on the lectotype of Lecidea (Biatora) obnubila Th. Fr. & Hellb., M. obnubila (Th. Fr. & Hellb.) Hertel & Rambold is a species with sessile apothecia with a hyaline hypothecium. Lecidea subplumbea Anzi does not constitute a heterotypic synonym of Lecidea griseoatra (Flot.) Schaer. but is the legitimate name at the species level for Miriquidica griseoatra sensu auct., and therefore M. subplumbea (Anzi) Cl. Roux is the correct name for that taxon. Lecidea inserena Nyl. is confirmed as a heterotypic synonym of Lecidea subplumbea Anzi. Lecidea plumbea Garov. ex A. Massal. is an earlier heterotypic synonym of Miriquidica limitata Hertel & Rambold and, therefore, the new combination M. plumbea (Garov. ex A. Massal.) Hafellner, Obermayer & Tretiach is introduced.

Lectotypes are designated for Lecidea contigua var. griseoatra Flot., Lecidea inserena Nyl., Lecidea obnubila Th. Fr. & Hellb., Lecidea plumbea Garov. ex A. Massal., and Lecidea subplumbea Anzi. A key to the taxa of the M. griseoatra-group and other Miriquidica taxa with a grey thallus is provided.

As part of a comprehensive biodiversity inventory of Galapagos lichens, all species in two closely related genera, Cryptothecia and Herpothallon, are reviewed. Both genera are superficially similar, ecorticate, cottony-byssoid crusts and are unusual insofar as their asci do not develop in distinct ascomata, but instead within ascigerous areas or even solitary inside pseudisidia. Species of Herpothallon typically have an I− medulla and are covered in ecorticate pseudisidia; only a single species is known fertile. Cryptothecia is characterized by ascigerous areas with loosely aggregated asci. In some species the asci are isolated, but others have closely aggregated asci embedded in a hyphal matrix with some carbonization, perhaps indicating preliminary stages towards a development of true ascomata. Lirellate ascomata of the enigmatic, monotypic Helminthocarpon leprevostii show similarity with these ascigerous areas, especially of C. darwiniana and C. galapagoana, two species newly described here. Both also have similar asci and ascospores. As previously suggested, Helminthocarpon should thus not be included in Graphidaceae, but it belongs in Arthoniales, possibly in Arthoniaceae or Opegraphaceae. A key to all species and brief descriptions are provided. Two of the three Cryptothecia species and two of the seven Herpothallon species reported here are new to science. All records apart from Herpothallon rubrocinctum are new to Galapagos and Ecuador.

Pannaria howeana and P. streimannii are described here as new to science. Both species are restricted to the isolated Lord Howe Island in Australia. The former is known only from one collection and the latter from two sites. Pannaria howeana is a primarily fertile species, with rather broad lobes and few rhizines restricted to the central part of the lower side of the thallus. The lower sides of the lobes have a pattern of characteristic radiating hyphae and narrowly recurved margins similar to the New Zealand lichen P. araneosa (C. Bab.) Hue, which is considered to be its closest relative. Pannaria streimannii is a phyllidiate counterpart of P. howeana. Both species share a new chemosyndrome consisting of porphyrilic acid in combination with vicanicin and leprolomin. Local endemic species are uncommon among tripartite Pannaria species, and the coarse vegetative propagules of both species appear to be an adaptation to local dispersal on a small, isolated island.

A corticolous lichen species, Opegrapha granulosa Siljo & G. P. Sinha, with a UV+ pale yellow thallus, is described as new to science from the Sundarbans Biosphere Reserve, West Bengal, India.

A preliminary study of the Lecanora dispersa group in Argentina is presented. Two species (L. dispersa and L. hagenii) have been previously recorded and their known distribution is extended, one species (L. semipallida) is a new record from Argentina, and five taxa (L. flowersiana, L. persimilis L. torrida, L. wetmorei and L. zosterae var. zosterae) are reported for the first time from South America. Three species (L. albescens, L. crenulata and L. populicola) previously recorded for Argentina have not been confirmed as occurring in this country. Lecanora aff. fugiens is also treated and compared to the related species. The morphology, anatomy, secondary metabolites, distribution and ecology of the nine studied taxa are described and discussed, and a key to the taxa is included.

Two new species of the lichen genus Carbacanthographis, namely C. albolirellata and C. indica, are reported from India. The two species are distinguished by their exciple character, ascospore septation and chemistry. Carbacanthographis albolirellata has a completely carbonized exciple, submuriform ascospores and no lichen substances. Carbacanthographis indica is characterized by a laterally carbonized exciple, trans-septate ascospores and by the presence of salazinic acid.

The new species Megaspora rimisorediata Valadbeigi & A. Nordin is described from Iran, where it mainly grows on tree bark but also on calciferous rocks and mosses. It is characterized by a pale ochraceous to bluish grey, cracked and sorediate thallus, very rarely producing ascomata. It appears to be rather commonly distributed in Iran. Its close affinity with Megaspora verrucosa is illustrated in a graph resulting from a phylogenetic network analysis of nuclear rDNA ITS1-5.8S-ITS2 sequences from specimens representing the different genera of Megasporaceae.

Two species of the lichen genus Carbacanthographis, namely C. marcescens and a new species, C. sorediata, are reported from India. The new species is characterized by a sorediate thallus, laterally carbonized exciple, submuriform ascospores, and salazinic and consalazinic acids in the thallus. A worldwide key to the species of Carbacanthographis is provided.

Herpothallon biacidum Frisch et al. is described from Queensland, tropical Australia. The new species is characterized by a thick byssoid thallus that is loosely attached to the substratum, globular to claviform to short cylindrical pseudoisidia, a brown to brownish black hypothallus, and by the presence of gyrophoric and norstictic acids. This is the first reported co-occurrence of gyrophoric and norstictic acids in the genus. The differences between H. biacidum and other species containing either norstictic acid or gyrophoric acid are discussed. Herpothallon biacidum is also compared with Cryptothecia eungellaeae. Both occur in north Queensland and have the same chemistry, but the latter has a closely adnate thallus and lacks the dark hypothallus and pseudoisidia. The circumscription of Herpothallon and its distinction from Cryptothecia are discussed.

Chrysothrix occidentalis Elix & Kantvilas, C. palaeophila Kantvilas & Elix and C. tchupalensis Elix & Kantvilas are described as new to science. In addition, the new combination Chrysothrix sulphurella (Räsänen) Kantvilas & Elix is proposed, C. granulosa G. Thor is reported for the first time from Australia (including Tasmania) and New Zealand, and C. xanthina (Vain.) Kalb for the first time from Tasmania, Norfolk Island and New Zealand. A key to the Australian species of Chrysothrix is presented. Chemical data on non-Australasian species of the genus are also provided.

Xanthoparmelia isidiovagans and X. subverrucigera from Spain are described as new to science. Both species are characterized by an isidiate upper surface and the presence of the stictic acid chemosyndrome in the medulla, but X. isidiovagans has a vagrant thallus with markedly revolute lobes with a black lower surface, whereas X. subverrucigera has adnate thalli with subirregular lobes and a brown lower surface.

The following new species of Parmeliaceae are described from Rwanda: Hypotrachyna rwandensis Elix, Eb. Fischer & Killmann and Parmotrema afrocetratum Elix, Eb. Fischer & Killmann.

Eight new species of Xanthoparmelia (Parmeliaceae) are described from eastern Australia: X. biloelensis Elix, X. fracticollis Elix, X. kosciuszkoensis Elix, X. nerrigensis Elix, X. paratasmanica Elix, X. rankinensis Elix, X. remanella Elix and X. stuartioides Elix. In addition, a further ten new state records of Xanthoparmelia are reported from eastern Australia.

The following new species of Xanthoparmelia (Parmeliaceae) are described from Western Australia: X. cranfieldii Elix, X. elevata Elix, X. kimberleyensis Elix, X. monadnockensisX. nanoides Elix, X. nortegeta Elix, X. sleei Elix and X. toolbrunupensis Elix. In addition, X. luminosa (Elix) Hale and X. Victoriana Elix & J. Johnst. are reported from Western Australia for the first time.