Phylloblastia inexpectata Sérus., Coppins & Lücking is a newly described foliicolous lichen, known from England, Scotland, Southern Italy and Madeira. It is distinguished from similar and related species by the absence of isidia and the smaller size of its ascospores. Phylloblastia pocsii is reported from Papua New Guinea for the first time.

Aspicilia uxoris is proposed as a new combination for a species known from Algeria, Morocco and Spain. It grows on bark and lignum of Cedrus atlantica, Juniperus spp. and Pinus halepensis in the western Mediterranean Region. It is characterized by spore and conidia sizes, granular epihymenium on the surface of paraphyses and a typical apothecial structure and development. The ecology and distribution of the species and a comparison with other epiphytic taxa of the genus are discussed. Notes on the identity of Aspicilia lignicola are provided. Lectotypes for Aspicilia cinerea var. vulgaris f. lignicola, Lecanora lignicola and Lecanora uxoris are designated.

The generic name Gemmaspora gen. nov. is introduced for the lichenicolous fungus originally described as Adelococcus lecanorae, a species previously known only from the type collection made in Syria in 1934, but which has now been recollected twice in Turkey. It is distinguished by perithecia that have a double wall layer in which the outer is hyaline and the inner brown, and by brown ascospores with two thick wall layers and an inner delicate distoseptum. A full description and illustrations are provided based mainly on the modern collections one of which is designated as an epitype for the name as no perithecia could now be found on the holotype. The genus is referred to Verrucariales on the basis of the structure of the ascomata and asci, and the new combination Gemmaspora lecanorae comb. nov. made. The holotype also supports Lichenostigma elongata and Muellerella lichenicola which may be the first reports of those two species from Syria.

Zwackhiomyces cervinae Calat., Triebel & Pérez-Ortega is described as new to science from Spain and Iran. This lichenicolous species grows on the lateral side of the squamules of Acarospora cervina, and it is characterized by its relatively large ascospores, which are brown when overmature. It is compared with several Zwackhiomyces species and with other taxa sharing some of its characters. A key to all the known species of the genus is also provided.

The new species Ramboldia blastidiata Kantvilas & Elix, from Tasmania and mainland Australia is described, and the new combination, R. elabens (Fr.) Kantvilas & Elix is proposed. The South American R. petraeoides var. concava (Müll. Arg.) Fryday is considered a synonym of R. petraeoides (Nyl. ex C. Bab. & Mitt.) Kantvilas & Elix s. str., and R. crassithallina Kalb and R. sorediata Kalb, both previously considered endemic to Western Australia, are recorded from Tasmania for the first time. A key to the 11 species of Ramboldia is presented.

Opegrapha species with muriform ascospores are revised and two species, differing only in the shape of their excipulum, are accepted: O. arabica, a widespread coastal species, and O. varians, known from mainland Yemen and Socotra. The genus Dictyographa, previously distinguished from Opegrapha by its muriform ascospores, is reduced into synonymy with Opegrapha. Dictyographa angolensis and D. sandwicensis are new synonyms of O. arabica; the type of D. cinerea was found to be a mixture of different species of the Hysteriaceae; and D. contortuplicata and D. psyllocarpa are excluded from the Arthoniales. Lectotypes are designated for D. angolensis, D. contortuplicata and D. sandwicensis.

The lichenicolous Phoma species on Cladonia are revised. A statistical analysis of the conidial size suggests that three species are involved: P. cladoniicola sp. nov. a common and widespread species in the Northern Hemisphere occurring on a wide range of Cladonia species; P. foliaceiphila sp. nov. known from C. foliacea and C. fimbriata in Europe; and P. grumantiana sp. nov. known from C. symphycarpia and C. mateocyatha in Svalbard and the USA.

Eighteen species in the lichen genera Acanthothecis Clem. and Fissurina Fée (Graphidaceae) with colourless, trans-septate ascospores are recorded from India. Eight new species, namely Acanthothecis collateralis, Fissurina capsulata, F. coarctata, F. karnatakensis, F. khasiana, F. longiramea, F. taeniocarpoides and F. verrucosa, and a new variety, F. dumastioides var. salazinica, are described. Fissurina saxicola ad int., clearly distinguished from the other species is recorded, but is not formally described as new to science as the material is scanty. Acanthothecis consocians, F. globulifica, F. insidiosa and F. rugosa are reported for the first time from India. A key for the trans-septate species of Acanthothecis and Fissurina in India is provided.

The new genus Aptrootia Lücking & Sipman is described for Thelenella terricola, an enigmatic terricolous and muscicolous, pyrenocarpous taxon known from Papua New Guinea and Costa Rica, and the new combination Aptrootia terricola (Aptroot) Lücking, Umaña & Chaves comb. nov. is introduced. Aptrootia is characterized by completely immersed perithecia with brown-black ostiolar region, surrounded by a white, cartilaginous thallus resembling that of Gomphillaceae. The hamathecium is typical of Trypetheliaceae, with thin, anastomosing paraphysoids embedded in a gelatinous matrix, but the dark brown ascospores are otherwise unknown within the family. The only known species was tentatively described in Thelenella, but hamathecium type and molecular data place Aptrootia within Trypetheliaceae.

In two lichen species, Hypogymnia physodes and Lecanora conizaeoides, often used as model organisms for pollution-sensitive and pollution-tolerant epiphytic lichens, respectively, the hypothesis was tested that the toxitolerance of the Trebouxia photobiont limits the tolerance of the entire lichen symbiosis. Being lecanoralean-trebouxioid associations, H. physodes and L. conizaeoides represent the most common type of lichens. Photobionts of both lichen species deriving from microhabitats with varying supply of S and heavy metals were identified using nuclear ITS nrDNA sequencing. The photobiont of L. conizaeoides was identified as T. simplex, whereas the photobiont of H. physodes belongs to an undescribed Trebouxia species, related to T. jamesii subsp. angustilobata and provisionally named as T. hypogymniae Hauck & Friedl ined. Since T. hypogymniae ined. is also known from Lecidea silacea, which is characteristic of rock and slag with high heavy metal content, a high sensitivity of this alga to pollutants is unlikely to be a key factor for the relatively low toxitolerance of H. physodes. Furthermore, the photobiont cannot be crucial for the extremely high toxitolerance of L. conizaeoides, as T. simplex is also known from pollution-sensitive lichens of the fruticose genus Pseudevernia. These findings suggest that the photobiont is not generally a key factor determining pollution sensitivity in the most common type of lichen symbiosis. The high specificity for T. simplex in L. conizaeoides in existing populations of L. conizaeoides suggest that already established thalli could be a source of photobiont cells for re-lichenization.