The Caloplaca holocarpa group in the Nordic countries, except Iceland, is defined genetically using the nrlTS DNA gene. The members are analysed with regard to morphology, anatomy, ecology, and chemistry. The results show that C. holocarpa seems to be a very small group, but there are many morphologically similar species outside the group. Within the group several species have been confused, but it is shown that C. holocarpa, C. pyracea, and C. vitellinula are separate taxa. Caloplaca cerinella also belongs to the group whereas C. cerinelloides does not, but is included in the treatment because of its similarity to the former species. Caloplaca lithophila H. Magn. is a synonym of either C. holocarpa or C. vitellinula, most probably of the latter. Many specimens determined to C. holocarpa belong to Caloplaca oasis, but this species is shown to have much more variable morphology and wider ecology and distribution than previously understood. Caloplaca oasis has also been confused with C. polycarpa, which is similar, but morphologically and genetically distinct, even though related. Neither of the two species belong to the C. holocarpa group, but are related to the C. citrina group, not to the C. velana group as usually believed. Other species from northern and central Europe similar to C. holocarpa belong in other groups. The treated species are described and illustrated in colour. Distribution maps are given for the study area. A key to species in northern Europe similar to C. holocarpa is also provided.

Petractis nodispora is described as a new species, characterized by an endolithic thallus with Trentepohlia as photobiont, immersed apothecia, 3-septate, halonate ascospores, and very distinctive multicellular conidia. Nuclear ribosomal SSU and LSU sequences show that it is closely related to P. luetkemuelleri, but its relationship to the type species of Petractis, P. clausa, is unclear.

A thorough chemical, molecular and morphological study has been carried out on a problematic group in the genus Lepraria characterized by lobed, granular thalli with a raised rim and a preference for mosses, rocks and mineral soils in exposed, xeric habitats. The material examined was collected in seven countries of the Mediterranean-Macaronesian region, from chalk, carbonate rocks and derived soils (A-thalli), and from siliceous rocks and derived soils (B-thalli). The results of a phylogenetic analysis based on 93 ITS sequences (29 of which newly obtained) support the identification and the segregation of two taxa at species level, provisionally identified as Lepraria isidiata s. lat., (most of the A-thalli), and L. santosii s. lat. (B-thalli plus the remaining A-thalli), as the observed genetic variability is quite high. Three chemotypes were detected in L. isidiata s. lat., and seven in L. santosii s. lat. The two taxa are morphologically well characterized: in L. isidiata s. lat. the thallus is thicker and the propagules larger than in L. santosii s. lat. The first stages of thallus development from single propagules are described in both species. Some critical remarks are made about the increasing use of the species rank for taxa of Lepraria, which are morphologically and genetically scarcely characterized.

The species-level taxonomy of the genus Graphis sensu Staiger was revised using numerical taxonomy and cladistic techniques. In its current circumscription, Graphis includes more than 300 species and is characterized by lirellae with well-developed, carbonized labia usually concealing the disc and usually hyaline, I+ blue-violet, transversely septate to muriform ascospores. The study analyzed the importance of morphological, anatomical, and chemical characters for taxonomic purposes in the genus, both at species level and at the level of species groups and lineages. A phenotype-based cladistic analysis, combined with a novel method to estimate the degree of character state homoplasies prior to a cladogram, as well as a species ordination using non-metric multidimensional scaling (NMS), was performed to assess the delimitation of potentially natural groups within the genus. Contrary to previous views, the most important character complex characterizing potentially natural groups in the genus Graphis is lirellae morphology, whereas labia striation, excipulum carbonization, ascospore features, and secondary chemistry, vary greatly even in closely related species. Based on these findings, Wirth and Hale's concept of ‘sporomorphs’ is emended to generally characterize morphologically similar species that differ in a single character, such as labia striation (‘labiomorph’), excipulum carbonization (‘excipulomorph’), hymenium inspersion (‘inspersomorph’), ascospore size and septation (‘sporomorph’) and secondary chemistry (‘chemomorph’).

Enterographa fellhaneroides and E. meklitiae are described as new to science from Kakamega Forest in Western Kenya. The latter overgrows the thallus of a foliicolous non-filamentous Coenogonium and the former most probably has the same ecology. Both species appear to be closely related to E. brezhonega and E. epiphyllum.

Two species of Placopyrenium, P. cinereoatratum and P. formosum, occur on siliceous rocks at the margins of rivers and lakes. Placopyrenium cinereoatratum is sometimes parasitic on Staurothele fissa; P. formosum is described as a new species, and is initially parasitic on Aspicilia aquatica.

Two new conidial lichenicolous fungi are described from Spain: Lichenodiplis crespoae on Cyphelium notarisii and Minutoexcipula tephromelae on Tephromela atra. Lichenodiplis crespoae differs from all the described species of the genus in the narrower and shorter conidia, and the host Cyphelium notarisii. Minutoexcipula tephromelae is characterized by subglobose, conidiogenous cells occasionally bearing 1–2 long proliferating extensions, short conidia and by the host Tephromela atra.

A world-wide key to the genus Graphis is presented, based on extensive type studies and revision of several thousand historical and recent collections. A total of 330 species are accepted and included in the key, and a further 205 epithets are listed as synonyms. The structured key includes taxonomic information on type specimens of epithets considered to be synonyms of the accepted species. In addition, 28 species of other genera (Carbacanthographis, Diorygma, Dyplolabia, Glyphis) with carbonized excipulum and hyaline ascospores likely to be confused with Graphis are mentioned under the corresponding key couplets. Although the key is preliminary and some taxonomic and nomenclatural problems remain unresolved at this time, it should allow reliable identification of most specimens especially from tropical regions. The following 14 species are described as new: Graphis brahmanensis Aptroot sp. nov., G. cupei Vain. ex Lücking sp. nov., G. funilina Aptroot sp. nov., G. inspersolongula Aptroot sp. nov., G. leucaenae Aptroot sp. nov., G. lourdesina Aptroot sp. nov., G. myolensis Aptroot sp. nov., G. nadurina Aptroot sp. nov., G. norstictica Archer & Lücking sp. nov., G. sarawakensis Hale ex Lücking sp. nov., G. slendrae Hale ex Lücking sp. nov., G. subintermedians Hale ex Lücking sp. nov., G. subserpens Staiger sp. nov., and G. syzygii Aptroot sp. nov. In addition, 22 new combinations are proposed: Carbacanthographis cleitops (Fée) Lücking comb. nov., C. coccospora (Aptroot) Aptroot & Lücking comb. nov., C. induta (Müll. Arg.) Lücking comb. nov., C. triphoroides (M. Wirth & Hale) Lücking comb. nov., Graphis apoda (Zahlbr.) Lücking comb. et stat. nov., G. cremicolor (H. Magn.) Lücking & Archer comb. nov., G. enteroleuca (Ach.) Lücking comb. nov., G. evirescens (Redinger) Lücking comb. nov., G. galactoderma (Zahlbr.) Lücking comb. nov., G. ingarum (Vain.) Lücking comb. et stat. nov., G. isidiata (Hale) Lücking comb. nov., G. japonica (Müll. Arg.) A. W. Archer & Lücking comb. nov., G. kousyuensis (Horik. & M. Nakan.) Lücking comb. nov., G. negrosina (Vain.) Lücking comb. et stat. nov., G. oxyspora (Zahlbr.) Lücking comb. nov., G. plumbea (Zahlbr.) Lücking comb. nov., G. riopiedrensis (Fink) Lücking comb. nov., G. semirigida (Müll. Arg.) Lücking comb. nov., G. subradiata (Nyl.) Lücking comb. et stat. nov., G. subtecta (Nyl.) Lücking comb. et stat. nov., and G. sulphurella (Zahlbr.) Lücking comb. nov. Replacement names are established for six taxa: Graphis jeanmuelleri Lücking nom. nov. [≡ Graphina elegantula Müll. Arg., non Graphis elegantula Zahlbr.], Graphis neoelongata Lücking nom. nov. [≡ G. elongata Vain., non G. elongata Zenker], Graphis novopalmicola A. W. Archer & Lücking nom. nov. [≡ Graphina palmicola Müll. Arg., non Graphis palmicola Makhija & Adaw.], Graphis paralleloides Cáceres & Lücking nom. nov. [≡ G. rimulosa var. parallela Müll. Arg., non G. parallela Müll. Arg.], Graphis subalbostriata Lücking nom. nov. [≡ G. angustata var. albostriata Vain., non G. albostriata Vain.], and Graphis subvernicosa Lücking nom. nov. [≡ Opegrapha vernicosa Fée, non G. vernicosa Nyl.]. Three new synonyms are established for Glyphis substriatula (Nyl.) Staiger: Graphina sulcatula Müll. Arg., G. sulcatula var. conglomerata Müll. Arg., and G. bakeri Zahlbr.

The foliicolous genus Phylloblastia is recorded for the first time in the Iberian Peninsula where it is represented by three species: P. fortuita sp. nov. from several localities in the north-east of Spain, P. dispersa, a new record for Europe and reported for the first time outside the tropics, and P. inexpectata. A key to the European species is provided.

A new taxonomy of the Caloplaca citrina group in the Black Sea region is presented. It is based on the nrDNA ITS molecular data, chemistry (anthraquinone contents) and 20 morphological characters. Six species previously known in the region are accepted: Caloplaca arcis, C. calcitrapa, C. dichroa, C. flavocitrina, C. geleverjae, C. limonia. Five new species are described: Caloplaca arcisproxima, C. austrocitrina, C. communis, C. confusa and C. nigromarina. Seven further species, Caloplaca britannica, C. citrina, C. marina, C. maritima, C. microthallina, C. ora and C. phlogina are also treated briefly. Some maritime species known from the Atlantic coast of Europe are absent from the region, and, surprisingly, Caloplaca citrina s. str. could not be confirmed from the study area. A key to the species present in the region is provided, although morphological characters are of very limited value in this group. The variability and taxonomic importance of particular features are discussed. No significant differences in secondary chemistry were observed among the species.

Many examples of convergence and some semi-cryptic species were revealed by molecular data. The term ‘semi-cryptic species’ is introduced here into lichenology for those species which cannot be clearly diagnosed by their morphology, but which are determined by other characters, mainly by their ecology and distribution. We propose to describe formally such species, in spite of difficulties with subsequent morphological identification.

Caloplaca herbidella (Hue) H. Magn. and C. furfuracea H. Magn. are two isidiate, epiphytic species in the large genus Caloplaca. Caloplaca herbidella in a strict sense is normally grey and fertile with thick, somewhat coralloid isidia, but orange, sterile forms with thin isidia also occur. Caloplaca furfuracea is superficially similar morphologically to C. herbidella s. str. but has thinner, more granular isidia and generally a darker grey colour. Doubts have been raised as to whether C. furfuracea should be acknowledged as a proper species or incorporated in C. herbidella. Using morphometric methods and molecular analysis of the nrITS DNA gene we show that C. herbidella and C. furfuracea are two clearly separated species. Furthermore, the mainly sterile, orange form of C. herbidella can be regarded as a separate species that is here described as C. coralliza Arup & Åkelius. All three species are described in detail, including photographs and notes on their ecology. Finally, new distribution maps for Europe show that C. herbidella and C. coralliza are widespread in Europe, but the latter is probably less common than the former. Caloplaca furfuracea is clearly very rare in Europe with only few collections from Switzerland and Sweden, but seems to be more common in North America.

Bryoria fremontii and B. tortuosa are the only species in the lichenized ascomycete genus Bryoria known to contain the pulvinic acid derivative vulpinic acid. In B. fremontii this yellow pigment is restricted to the soralia and apothecia, while in B. tortuosa it can occur throughout the thallus. The actual amount of vulpinic acid produced by B. tortuosa is rather variable, however, with intermediate specimens bearing both white and yellow pseudocyphellae. We studied the relationship between the two species with parsimony analysis using four DNA regions: 1) the internal transcribed spacers of the nuclear rDNA including the 5.8S region (ITS), 2) partial sequences from the intergenic spacer of the nuclear rDNA (IGS), 3) partial sequences from the small subunit of the mitochondrial rDNA (mtSSU), and 4) partial sequences from the protein-coding glyceraldehyde-3-phosphate dehydrogenase gene (GAPDH). Our phylogenetic analysis revealed that B. fremontii and B. tortuosa must be regarded as conspecific, but allowing for some genetic differentiation between European and North American populations. Bryoria tortuosa is therefore synonymized with B. fremontii.

The silicicolous lichen species, Rinodina etayoi Giralt & van den Boom, is described as new from inland localities of Fuerteventura and Lanzarote (Canary Islands). It is characterized by a crustose, whitish thallus containing atranorin, zeorin, chloroatranorin and stictic acid, hemispheric pseudolecanorine apothecia containing, a proper exciple inspersed with numerous and large oil drops, and by ascospores of the Mischoblastia-type. The joint occurrence of pannarin, stictic acid and Mischoblastia-type ascospores makes R. etayoi unique within the genus.

A comparative review of 57 Lepraria species and 2 varieties is provided together with species descriptions and a key. Lecanora leuckertiana is transferred to Lepraria. In addition some putative taxa by different authors are discussed.

Lecanactis rubra is described as new to science. It is characterized by having rounded to irregular or lirellate ascomata, relatively wide 3-septate ascospores and by the production of gyrophoric acid and an anthraquinone. The species is known only from the type locality in the deciduous dry forests in the western part of Madagascar.

Five new species of Cryptothecia: C. alboglauca, C. bengalensis, C. farinosa, C. multipunctata and C. verruculifera, and two new species of Herpothallon: H. granulosum and H. isidiatum are described from India. Herpothallon australasicum (Elix) Elix & G. Thor and H. granulare (Sipman) Aptroot & Lücking are also reported as new records.