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 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 species of Lecanora sensu stricto occurring in Thailand are revised. Twenty-eight species are accepted with one new species, L. kansriae described for a taxon with small crystals in the amphithecium and containing the stictic acid chemosyndrome. Eight species are recorded from Thailand for the first time: L. coronulans, L. farinacea, L. interjecta, L. leproplaca, L. melaleuca, L. plumosa, L. pseudargentata, and L. toroyensis. Previous records of L. casuarinophila, L. insignis, L. pulicaris, and L. subgranulata are shown to be based on misidentifications. The new combination Vainionora flavidorufa is proposed for Lecanora flavidorufa Hue (syn. L. lividocarnea Vain. and L. lividoglauca Vain.). A key for the identification of the treated species is provided.

Two new species, Lecanora hafelliana L. Lü, Y. Joshi & Hur and L. loekoesii Y. Joshi, L. Lü & Hur, are described as new to science from South Korea and eight species, L. campestris (Schaer.) Hue, L. cenisia Ach., L. nipponica H. Miyaw., L. perplexa Brodo, L. plumosa Müll. Arg., L. polytropa (Hoffm.) Rabenh., L. subrugosa Nyl. and L. sulcata (Hue) H. Miyaw., are recorded from South Korea for the first time. Lecanora hafelliana is characterized by the presence of hafellic acid, which is reported for the first time in this genus, while L. loekoesii is characterized by multispored asci and a thallus containing norstictic acid.

The new genus Halegrapha is introduced, with six species (five new species and one new combination) from Australia, the Philippines, Malaysia, Kenya, Mexico, and the United States: H. chimaera Rivas Plata & Lücking (type species; Philippines), H. floridana Common & Lücking (United States: Florida), H. intergrapha Hale ex Lücking (Malaysia), H. kenyana Kalb & Lücking (Kenya), H. mexicana A. B. Peña & Lücking (Mexico), and H. mucronata (Stirt.) Lücking (Australia). The genus resembles Graphis morphologically in the strongly carbonized, black lirellae and white-grey thallus strongly encrusted with calcium oxalate crystals, but has a Phaeographis-type hymenium (clear in two species) and ascospores, making it a ‘chimera’ between the two genera. Molecular data suggest the genus to be closely related to Phaeographis and allies but genetically distinct from any of the genera currently recognized, including Platygramme.

Based on morphological, anatomical, chemical, ecological and molecular evidence, Blarneya is synonymized here with Tylophoron. The molecular phylogeny derived from sequences obtained from sporodochia of Blarneya places this genus, described to accommodate an anamorphic lichen with white cushion-shaped sporodochia, within Tylophoron. This conclusion is further supported by the discovery of Tylophoron-type ascomata emerging directly from thalli with Blarneya-type sporodochia and producing identical hyaline conidia. In one specimen pycnidia were also observed. This represents a surprising variety of morphologically different conidiomata. A different anamorphic type was previously reported from Tylophoron, and this is confirmed here by molecular analysis for T. moderatum: besides thalli with ascomata this species has anamorphic thalli with an irregularly delimited brown sporodochial felt and brown conidia. Ascomata are not known from these entirely anamorphic thalli, whereas they do occur infrequently in Tylophoron species with Blarneya-type sporodochia. A key to all currently accepted species of Tylophoron is provided. In addition to the corticolous Tylophoron hibernicum, confined to humid forests, two saxicolous species with Blarneya-type sporodochia are described here as new: T. galapagoense, known only from Galapagos, differs from T. hibernicum by a thicker, more compact, beige rather than white, more strongly C+ red thallus, growing below sheltered rock overhangs in dry forests; T. stalactiticum has a C− thallus with stipitate, white, C+ red sporodochia; the species is known only from a single locality in Tenerife, on a large slope with volcanic boulders.

The lichen genus Sporodochiolichen is installed to accommodate a group of four, so far undescribed, tropical corticolous lichen species with arthric conidia in discrete sporodochia. Three species are so far only known from Papua New Guinea; one is known from five countries on two continents and is probably pantropical.

The new lichenicolous fungus Llimoniella cinnabarinae growing on Ramboldia cinnabarina from Alaska is described. The lack of excipular or epihymenial K+ purplish, violet or green pigments places it near the recently described L. phaeophysciae group. Its affinity with Llimoniella and other members of lichenicolous Helotiales is discussed.

To date, there have only been two endemic species of the lichen genus Porpidia known from the maritime Antarctic. A new endemic species, Porpidia submelinodes Osyczka & Olech, recognized in the South Shetlands and South Orkneys, is described in this paper. The species is primarily characterized by its rusty orange, sorediate thallus, composed of convex, well separated and rounded areoles, and by the absence of lichen secondary products detectable by TLC. The morphology and soralia of this new species correspond to the arctic-alpine and boreal-mountain lichen Porpidia melinodes. The paper also discusses the differences between these two taxa and all Porpidia species reported from Antarctica.