After a discussion of changing generic concepts in the parmelioid lichens, a checklist with the current species placements is presented. Twenty-five genera and 143 species are accepted for Europe, of which 17 genera and 112 species belong to the monophyletic parmelioid clade. The individual countries from which species are reported are provided, along with references to key publications. Synonyms used at species rank in Europe are cross-referenced, and the dates of publication of all names are provided. One new combination is made: Xanthoparmelia pulvinaris (syn. Parmelia pulvinaris, X. pseudohungarica).

The new genus Atla forms a well-supported clade in a molecular phylogeny based on the ITS1-5.8S-ITS2 and LSU regions of the nuclear ribosomal DNA. The genus has a crustose thallus, a hamathecium at maturity without hyphal elements except for pseudoparaphyses remaining at the ostiolum, and large, muriform spores. Atla wheldonii was previously referred to Polyblastia. Three new species, A. alpina (the type of the new genus), A. palicei and A. praetermissa, are included in the genus and described here as new to science. They were found on calcareous rocks and soil in Northern Scandinavia; A. alpina also occurs in Central Europe, and A. wheldonii likewise in Central Europe, the Pyrenées and in the British Isles. An identification key to the species and a revision of the genus are also provided.

The name Polycoccum opulentum proves to have been wrongly applied to a lichenicolous fungus belonging to the genus Lichenothelia, and which differs from the type material of P. opulentum in having non-ostiolate broadly stipitate ascomata and narrow ascospores with a conspicuous gelatinous sheath. The Lichenothelia represents an hitherto undescribed species, named here as L. renobalesiana, sp. nov. which is associated with verrucarialean lichens on hard limestones in temperate regions. The true P. opulentum is known only from the original collection on Polyblastia hyperborea from Sweden.

The preparation of the new edition of The Lichen Flora of the British Isles necessitates the publication of several taxonomic and nomenclatural novelties. The following new species are described: Anisomeridium robustum (Monoblastiaceae), Antennulariella lichenisata (Antennulariellaceae), Fellhanera duplex (Pilocarpaceae), Gyalideopsis crenulata (Gomphillaceae), Micarea farinosa (Pilocarpaceae) and Xerotrema quercicola (Odontotremataceae). Antennulariella lichenisata is the first lichenized member of the order Capnodiales to be described. The following new combinations are proposed: Bacidia squamellosa, Catillaria lobariicola, Collemopsidium arenisedum, C. argilospilum, C. caesium, C. chlorococcum, C. monense, C. subarenisedum, Miriquidica pycnocarpa f. sorediata, Pyrenocarpon thelostomum, Topeliopsis azorica, and Verrucaria nigrescens f. tectorum.

A revision of the Lecanora saligna-group is provided, based on specimens mainly from western and central Europe. Four new Lecanora species related to L. saligna are described: L. calabrica, L. coppinsii, L. pseudosarcopidoides and L. subsaligna, as well as a new variety, L. albellula var. macroconidiata. The species treated have in common relatively short and ± curved or bacilliform conidia and/or isousnic acid as a secondary metabolite. Species without isousnic acid, containing exclusively filiform conidia are excluded. Notes on various types of conidia (macroconidia, microconidia, mesoconidia and leptoconidia), morphology, ecology, chemistry and distribution are given and a key to the treated species is provided. Detailed descriptions are presented for eight related species in order to highlight the distinguishing characters.

Fifty-six known lichenicolous, non-lichenized Opegrapha (Roccellaceae, Arthoniales) species (containing some undescribed taxa) are listed here, five of which are known from Caloplaca (Teloschistaceae, Teloschistales). Opegrapha vulpina, a new lichenicolous fungus on endolithic Caloplaca subg. Pyrenodesmia (Caloplaca erodens and rarely C. albopruinosa), is described from Europe. A second new species, Opegrapha hellespontica, lichenicolous on Caloplaca aurantia, is described from the European part of Turkey. Two possible sibling species of Opegrapha rupestris s. l. lichenicolous on Caloplaca cirrochroa and C. variabilis s. l., respectively, are discussed in the paper, but have not been described.

Caloplaca concreticola is described here as new. It is a morphologically well-characterized, sorediate species of the subgenus Pyrenodesmia, that comprises a part of the ‘‘black-fruited’’ taxa with an absence of anthraquinones in their apothecia. Currently it is known only from concrete and always occurs close to water (mainly on the walls of water channels). Analysis of nuclear ribosomal ITS sequence data of the new species, together with most European species of the subgenus, supports the recognition of the new species as a monophyletic taxon within the Pyrenodesmia clade.

We describe Calicium sequoiae as a new species of lichenized Ascomycota from north-western California, USA. The species is distinguished morphologically from other known members of Calicium by its stalks that react I+ blue, mature ascospores that are ornamented with spiral ridges, and apothecia that produce prominent white pruina. It is also the only Calicium known to produce thamnolic acid as a major secondary substance. Sequences from the ITS-region showed C. sequoiae to be unique among calicioid Physciaceae, and phylogenetic analysis positioned it close to C. adspersum, C. chlorosporum, C. lenticulare, Cyphelium notarisii, and C. tigillare. Thus far, Calicium sequoiae has been collected only from old-growth redwood (Sequoia sempervirens) forests, where it occurred on thick, fibrous bark of large redwood trees. A key to the 12 species of Calicium known from the Pacific Northwest is provided.

The morphological circumscription of selected Central European freshwater species in the lichen genus Thelidium was re-examined against the background of a molecular phylogeny based on ITS sequences. Molecular data reveal a close relationship between Thelidium methorium, T. pertusatii and Verrucaria latebrosa contradicting the traditional separation of Verrucaria and Thelidium by ascospore septation. Thelidium methorium and T. pertusatii are closely related species. The distinction of Thelidium methorium and T. submethorium was supported both by differences in ITS sequences and morphology. Thelidium minutulum, T. pluvium and T. zwackhii form a distinct clade with small perithecia and a thin or absent involucrellum. Thelidium rehmii and T. minutulum differ morphologically only in larger variability of ascospore length and the arrangement of photobiont cells, but are clearly separated by their ITS sequences as well their ecological requirements. An identification key for epilithic freshwater species of Thelidium in Central Europe is given, a lectotype for T. pertusatii is chosen, and detailed remarks for each species are provided.

The new species Miriquidica effigurata, M. squamulosa and Pertusaria stellata are described from the southern subpolar region from collections made by Henry Imshaug and co-workers in the early 1970s. All three species occur on Campbell Island, New Zealand, with M. effigurata and P. stellata also occurring on the Auckland Islands, New Zealand, and P. stellata also being reported from Isla Desolación in southern Chile. Miriquidica effigurata and M. squamulosa are similar to M. complanata but have apothecia with a dark (K+ purple-red) lower hypothecium and thalli containing confluentic acid and norstictic acid respectively. Pertusaria stellata is similar to P. macloviana, but has shorter ascospores and a smoother, generally paler thallus lacking papillate isidia. Cephalodia are reported for the first time in both Miriquidica and Pertusaria.

Two new species, Mazosia lueckingii Kr. P. Singh & Pinokiyo and Sporopodium awasthianum Kr. P. Singh & Pinokiyo and a new variety, Aspidothelium scutellicarpum R. Lücking var. indicum Kr. P. Singh & Pinokiyo, are described.

Caloplaca subalpina Vondrák, Šoun & Palice and C. thracopontica Vondrák & Šoun are described here as new to science. The former is a sorediate, often sterile, saxicolous species inhabiting subalpine base-rich overhanging rocks in European mountains; the latter grows on maritime cliffs of the Black Sea and is conspicuous by the lobules and pustules which are usually present on its thallus and by its apothecia which are typically large and abundant. The placing of the two species in the C. cerina group was confirmed by molecular studies using nrDNA ITS sequences. The chemosyndromes of both new species correspond to chemosyndrome A, which is in accordance with their position in the C. cerina group. A key to the saxicolous species of the C. cerina group is provided.

The species of the genus Fuscidea occurring in North America are revised. Two new species, Fuscidea appalachensis Fryday and F. texana Fryday, are described from eastern North America and southern Texas, respectively. Three new combinations are also made in Fuscidea: Lecidea aleutica Degel. is shown to be a distinct species and not a synonym of Fuscidea lowensis (H. Magn.) R. Anderson & Hertel as previously suggested and is here recognized as F. aleutica (Degel.) Fryday; non-sorediate, apotheciate specimens from eastern North America previously referred to F. recensa (Stirt.) Hertel, V. Wirth & Vězda are recognized as Fuscidea recensa var. arcuatula (Arnold) Fryday; and Fuscidea scrupulosa (Eckf.) Fryday is shown to be the correct name for Fuscidea subreagens (H. Magn.) Oberholl. & V. Wirth. Fuscidea subfilamentosa (Zahlbr.) Brako is shown to be a member of the Lecidea hypnorum group and the new combination Lecidea subfilamentosa (Zahlbr.) Fryday is made, and Lecidea gyrodes H. Magn., described from Tennessee, is shown to be a synonym of F. recensa var. arcuatula. Fuscidea cyathoides (Ach.) V. Wirth & Vězda, F. kochiana (Hepp) V. Wirth & Vězda and F. lightfootii (Sm.) Coppins & P. James are considered not to have been correctly reported from North America.

Four species of Eschatogonia are recognized in Peru: E. angustiloba Timdal sp. nov., E. dissecta Timdal & R. Sant. sp. nov., E. minuta Timdal & R. Sant. sp. nov., and E. prolifera (Mont.) R. Sant. African and South American material of E. prolifera are shown to belong in two different chemical strains. Eschatogonia prolifera is new to Guinea, Peru and Suriname. A key to all six known species of the genus is given.

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.

The new lichen genus Myochroidea is described to accommodate four species of the Lecidea leprosula group. Myochroidea is characterized by a crustose, areolate, minutely crenate to almost coralloid or indistinct, grey-brown to olive-brown thallus, reddish brown apothecia with an often persistent margin, moderately branched and anastomosing paraphyses with often swollen, pigmented apical cells, asci of the Micarea-type, and colourless, one-celled, fusiform to broadly ellipsoid ascospores. The new combinations Myochroidea leprosula (Arnold) Printzen, T. Sprib. & Tønsberg comb. nov., M. porphyrospoda (Anzi) Printzen, T. Sprib. & Tønsberg comb. nov., M. rufofusca (Anzi) Printzen, T. Sprib. & Tønsberg comb. nov. and the new species M. minutula Printzen, T. Sprib. & Tønsberg are published. Lecidea porphyroplaca Hinteregger & Poelt is a synonym of M. rufofusca. Descriptions of the four species and an identification key are provided. Myochroidea leprosula and M. rufofusca are reported as new to North America.

The coelomycete Acaroconium punctiforme gen. sp. nov. is described from four members of the lichen-forming family Acarosporaceae, three species of Acarospora and Sarcogyne regularis. The new fungus is characterized by pycnidial conidiomata with a distinct ostiolar collar, enteroblastic conidiogenesis, and the production of simple brown conidia. The separation of the fungus from other somewhat similar pycnidial fungi growing on lichens and plant material is discussed.

Ameliella Fryday & Coppins gen. nov. is proposed to accommodate two inconspicuous, undescribed species, A. andreaeicola and A. grisea, collected from high altitude in the Scottish Highlands. Outside the Scottish Highlands, Ameliella andreaeicola is known from single collections from Norway and Canada, and A. grisea from a single collection from Norway. The new genus appears to have some affinity with Miriquidica.

The xanthorioid taxa Xanthomendoza borealis and Xanthoria mawsonii are revised using morphological, anatomical, secondary chemical, and molecular characters. We conclude that most specimens determined as X. mawsonii from the Antarctic are conspecific with specimens labelled X. borealis from the Northern Hemisphere. Some specimens named X. mawsonii from the Antarctic are wrongly determined specimens of Xanthoria candelaria (L.) Th. Fr, including the holotype of Xanthoria mawsonii C. W. Dodge. Accordingly, Xanthoria mawsonii C. W. Dodge is a synonym to Xanthoria candelaria (L.) Th. Fr. The only available correct name for the bipolar species, which comprises material previously determined as X. borealis and X. mawsonii, and is distinct from the more widespread taxon X. candelaria, is Xanthomendoza borealis (R. Sant. & Poelt) Søchting, Kärnefelt & S. Kondratyuk.

The new species Parmeliella subfuscata A. Dube & Makhija, belonging in the P. mariana group, is described. It is recognized by its squamulose, loosely attached, spreading, brownish thallus with cylindrical, branched isidia, indistinct, black prothallus of slightly projecting rhizohyphae, and its apothecia with an unusual, fresh green coloured epithecium and proper exciple. It is so far known only from the type locality in Maharashtra, India.