Bacidia adastra Sparrius & Aptroot is newly described from the Netherlands, Belgium, England and Germany. It is related to Bacidia arnoldiana s. lat. and differs from Bacidia caligans, B. neosquamulosa and B. viridescens by thallus structure and pigmentation of the excipulum and epithecium. It usually grows on acid or neutral, eutrophicated bark. It is characterized by the remarkable, pale green, thick, leprose thallus, the pale apothecia with aeruginose or dark brown flecks in the epihymenium and excipulum, and the hyaline hymenium and hypothecium.

Since the last compilation in 1983, the number of lichenicolous fungi (and lichenicolous lichens) recorded in Great Britain and Ireland has increased from 218 to 403 species (a rise of 85%). The introduction includes accounts of: the history of investigation, circumscription, phylogenetic relationships, symbiotic interactions, dispersal and establishment, distribution, culture, host restriction, and identification. The checklist enumerates the recorded species. Information is provided on the systematic position of each genus, together with the authors and dates of publication of all accepted names; synonyms used in the literature of the two countries since 1910 are cross-indexed. References to pertinent literature with descriptions and discussions are included, together with notes on particular species. The list of references cited includes 298 publications. The following new scientific names are introduced: Diederichia gen. nov., and Dactylospora scapanaria (syn. Lecidea scapanaria), Diederichia pseudevemiae (syn. Macrophomina pseudeverniae), Muellerella ventosicola (syn. Microthelia ventosicola) and Nigromacula uniseptata (syn. Vouauxiella uniseptata) combs, nov.

Two new species of Mycobilimbia are described from Spain. Mycobilimbia olwacea has a minutely squamulose and olivaceous thalli and dark reddish brown apothecia, colourless inside; it has been found at middle to high altitudes (from 900 to 1750 m), growing on humid tree bases of Pinus nigra and lignum of Quercus pyrenaica. Mycobilimbia parvilobulosa is closely related to M. berengeriana, but differs markedly by its squamulose thalli, with crenate to subdigitiform margins, dark reddish brown excipulum and colourless epithecium. It grows on moss-covered old trunks of fagaceous trees. The new taxa are compared with M. berengeriana, M. hypnorum and M. sanguineoatra and their main distinguishing characters are tabulated.

Two new corticolous species, Hafellia alisioae and H. gomerana (lichenized Ascomycetes, Physciaceae), collected from twigs of coastal shrubs on the Canary Islands are described. The new species are discussed in relation to other Hafellia species with similar characters. An overview and a key for 23 corticolous species of Hafellia with 2-celled ascospores is provided.

Lecanora zosterae (Ach.) Nyl. is a distinct species belonging to the Lecanora dispersa group. In the British Isles it is confined to the coast where it grows mostly on the exposed turf above sea cliffs. Some 76% of the population occurs on decayed thrift Armeria maritima. The related Lecanora umbrina (Ach.) A. Massal. is lectotypified; it is the correct name for Lecanora hagenii auct.

Lichenostigma radicans Calat. & Barreno, a lichenicolous fungus growing on vagrant Aspicilia species, is described as new to science from Spain. It is superficially similar to L. maureri, with cushion-like ascomata, but differing mainly by its ascomata connected at their base to immersed, brown, vegetative hyphae. Comments on the variability of iodine reactions of asci and ascospore walls, and on an associated conidial fungus with small bacilliform conidia, are given for L. maureri.

The African continent is shown to contain only 38 species in the lichen family Pannariaceae, all of which are listed in the conclusion. Four new species are described: Pannaria planiuscula (Republic of South Africa [RSA] and Kenya), Pannaria squamulosa (RSA), Parmeliella dactylifera (RSA), and Parmeliella triptophylloides (Kenya). Four species are recorded as new to the continent: Pannaria centrifuga P.M. Jørg. (RSA), Pannaria ramosii Vain. (Tanzania), Parmeliella imbricatula (Müll. Arg.) P. M. Jørg. (RSA), and Psoroma fruticulosum James & Henssen (RSA). The following taxa described from Africa prove to be synonyms: Pannaria cameroonensis Dodge (=Parmeliella stylophora), Pannaria capensis Stirt. (= P. lurida), Pannaria leucosticta var. isidiopsis Nyl. (= P. globigera), Pannaria pityrella Stirt. (= Coccocarpia stellata), and Pannaria thoroldii Dodge (= Parmeliella mariana). Three species have been incorrectly recorded from Africa: Pannaria fulvescens, Parmeliella nigrocincra and Parmeliella triptophylla.

Seven Neofuscelia species have been identified from Italy. A key to the species is provided and the distinguishing morphological and chemical characters, distribution, ecology, substratum preference and interrelationships of each are discussed. Neofuscelia perrugata is new to Italy. N. pyrenaica is new to Greece and Cyprus. New data on the distribution and ecology of N. perrugata, N. delisei and N. luteonotata are presented and these are consistent with their taxonomic rank.

Pyrenula luteopruinosa Etayo & Aptroot is described as new from lowland rainforest on the Pacific coast of Panama. The new name Pyrenula caraibica Aptroot & Etayo and the new combinations Pyrenula chilensis (Fée) Aptroot & F. Berger, Pyrenula cryptothelia (Müll. Arg.) Aptroot & Etayo and Pyrenula hibernica (Nyl.) Aptroot are proposed.

Arctomia teretiuscula sp. nov. (Arctomiaceae) is described from Sichuan Province, China. A minutely coralloid, bryophilous cyanolichen, it is a further example of the biogeographical link between the lichen biotas of the Himalayan region and the Arctic. A key to the three accepted species of Arctomia is provided.

Stigmidium cartilagineae Calatayud &Triebel (on the apothecial discs of Squamarina cartilaginea), a lichenicolous fungus belonging to Stigmidium s. str., is described as new. Two other species of Stigmidium s. 1. with a net of branched and anastomosing, rudimentary interascal filaments are also described as new to science: Stigmidium rouxianum Calatayud & Triebel (on Acarospora cervina) and S. squamarinicola Calatayud & Triebel (on the thallus of Squamarina spp.). They are related to Stigmidium psorae and treated here as ‘Stigmidium’ psorae group. To facilitate discussion of the distinguishing features of this group, a table comparing the terms referring to hamathecial hyphae in pyrenocarpous ascomycetes is presented.

The new species Ochrolechia splendens Lumbsch and Messuti, is described from Mexico, south-western North America, where it occurs on exposed siliceous rocks. It is characterized by relatively large apothecia with entire margins, the presence of the gyrophoric acid chemosyndrome in the thallus and apothecial disc and the presence of lichexanthone as major components.

The paper deals with six species of Parmotrema from India. Parmotrema awasthii Divakar & Upreti and Parmotrema upretii Divakar are described as new to science. Parmotrema defectum (Hale) Hale, P. ravum (Krog & Swinscow) Sérus., P. stuhlmannii (C.W. Dodge) Krog & Swinscow and P. tsavoense (Krog & Swinscow) Krog & Swinscow, are new records for the Indian lichen flora.

Trichothelium longisetum sp. nov. (Porinaceae) is described from a rainforest in northeastern Ecuador. It has a non-radiating photobiont, prominent, black perithecia, each with numerous, long-acute to acicular, black setae, and elongate-bacilliform, 9–15-septate ascospores. Remarkably, this lichen grows on wood rather than on the living leaves or bark of trees or shrubs. Four species of Porina are also reported for the first time from Ecuador.

Chroodiscus lomatiae Messuti, Lumbsch & Vezda is described as new to science. This southern South American species belongs to the family Thelotremataceae. It is characterized by fusiform, hyaline, small, thin-walled ascospores, exfoliating, chroodiscoid apothecia, and the presence of lecanoric acid.

Studies of type specimens and other specimens of Menegazzia subsimilis and M. dissecta have shown that they are referable to the same taxon. Thus, M. dissecta is reduced to synonymy with M. subsimilis, which is characterized by lacerate soralia protruding from lobe apices or vertical lobules (protuberances), small perforations and the presence of the stictic acid complex in the medulla. It has 2-spored asci. The synonymy implies that M. subsimilis has a much wider distribution range than previously known. It is reported here from Oceania (Hawaii, Solomon Islands), Asia (Japan, Papua New Guinea, Russia), Europe (Austria, Germany, Portugal), South America (Ecuador, Peru), the Caribbean (Dominican Republic, Jamaica) and North America (Canada, USA).

The morphology, anatomy, ecology and distribution of Buellia tesserata and Dimelaena radiata are discussed. New data on their chemistry are given. The present study reveals a very close relationship between both taxa and consequently their different generic position is questioned. Buellia fimbriata is reduced to synonymy with Buellia tesserata.

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.

The phylogeny of the genus Diploschistes was investigated using nucleotide sequences of the nuclear ITS rDNA region (ITS1, ITS2 and 5.8S rDNA). Sequences of 22 Diploschistes species were aligned to those of six other species of Thelotremataceae, Graphis scripta and Aspicilia cinerea, with the last used as an outgroup. The alignment was analysed cladistically using maximum parsimony. In the most parsimonious trees, Diploschistes is monophyletic, with D. ocellatus being a sister group to the remaining Diploschistes spp. (= Diploschistes s. str.). A previous cladistic analysis of morphological data suggested an evolutionary trend within the genus from perithecioid to urceolate ascomata. The present ITS data suggest the opposite: perithecioid ascomata are apparently an apomorphic character within the genus, with the actinostomus group forming a derived monophyletic clade. However, the topology within Diploschistes s. str. Lacks strong bootstrap support.