Iberian records of Buellia triseptata A. Nordin are presented. This corticolous and lignicolous species was recently described from North America. A description based on the Iberian material is given, together with notes on ecology and distribution. Specimens belonging to B. triseptata were previously reported as B. disciformis, B. lauricassiae, B. pharcidia and B. triphragmia. The main distinguishing features between these taxa and B. triseptata are pointed out, and background to the misapplied names is given. Illustrations of the ascospores of B. triseptata and B. lauricassiae are presented. A distribution map of B. triseptata in the Iberian Peninsula is also provided.

Three species of the genus Dactylospora, D. crassa Sarrion & Hafellner, D. mediterranea Sarrión & Hafellner, and D. pseudourceolata Sarrión & Hafellner are described as new from Spain. The morphology, anatomy, and ecology of the three taxa are discussed. A key to the Spanish Dactylospora species is provided.

Byssoloma llimonae, a new species described from NE Spain, Madeira and the Canary Islands (Gomera, La Palma and Tenerife), is a mostly corticolous species, closely related to the more widespread and usually foliicolous Bapalmuia kakouettae (=Byssoloma aptrootii). The generic position of this group of species within the Pilocarpaceae is still unclear. The new combination Byssoloma kakouettae (Sérus.) R. Lücking & Sérus. is introduced.

Rhizocarpon hochstetteri s. str. is shown to be an upland/montane species with relatively large ascospores. The name Rhizocarpon infernulum is resurrected for the species with smaller ascospores previously included within R. hochstetteri, but which is probably more closely related to R. cinereovirens. Lectotypes are chosen for a number of taxa, including R. cinereovirens and R. infernulum, and descriptions provided for two new taxa with small hyaline, 1–septate ascospores: R. caesium, which occurs on damp, mildly basic rocks in oceanic areas, and R. infernulum f. sylvaticum occurring on siliceous rocks in damp deciduous woodlands. All these taxa are known also from North America. Rhizocarpon discoense is shown to be a distinct species, not a synonym of R. cinereovirens. The different ascospore dimensions reported for R. hochstetteri by British and European authors are shown to be due to confusion between R. hochstetteri and R. polycarpum. A number of morphological characters are evaluated regarding their relevance to species separation in Rhizocarpon and the name Macrocarpa-green is proposed for the olivaceous pigment present in most species of Rhizocarpon and Porpidia. A key is provided for the species of Rhizocarpon with hyaline, 1– septate ascospores.

A description of the polysporous Buellia dives (Th. Fr.) Th. Fr. is provided. It is distinct from Buellia polysporella (Nyl.) Arnold, with which it has been placed in synonomy, by the lecideine (versus lecanorine) apothecia, the dark brown (versus colourless) hypothecium and the Buellia-type (versus Physcia-type) ascospores. Further, B. polysporella is shown to be conspecific with Rinodina polyspora Th. Fr. and is reduced to synonomy with that species. Buellia dives is reported as new to Norway and Spain and notes on its ecology and distribution are given.

The genus Lethariicola is shown to be a synonym of Odontotrema. Fifteen lichenicolous species are recognized: O. bryoriae sp. nov. (on Bryoria), O. cuculare comb. nov. (on Parmeliopsis hyperopta), O. figulinum comb. nov. (on Lecanora polytropa) O. intermedium sp. nov. (on Thamnolia), O. lecanorae sp. nov. (on Lecanora), O. melaneliae sp. nov. (on Melanelia), O. ochrolechiae sp. nov. (on Ochrolechia), O. pertusariae sp. nov. (on Pertusaria hymenea), O. rhizocarpicola sp. nov. (on Rhizocarpon) O. santessonii sp. nov. (on Thamnolia), O. sipei comb. nov. (on Letharia), O. thamnoliae sp. nov. (on Thamnolia), and three undescribed species on Lecanora, Mycoblastus and Usnea. The type of O. cuculare has two distinct lichenicolous species of Odontotrema, and the name is lectotypified on the species growing on Parmeliopsis. A key is given to all lichenicolous species of Odontotrema and Paralethariicola.

Szczazvinskia leucopoda Holien & Tønsberg and 5. foliicola Holien & Tønsberg are described from coastal Central Norway and Newfoundland, and from Papua New Guinea, respectively.

The new combination Stereocaulon cumulatum (Sommerf.) Timdal is made for the northern Eurasian and Greenlandic, arctic-alpine, terricolous lichen presently known as Toninia cumulate (Sommerf.) Th. Fr.

Eleven Xanthoparmelia 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. Xanthoparmelia cumberlandia is reported for the first time from Europe; X. angustiphylla and X. plittii are new to Italy.

The new lichen species Cladonia krogiana is described from eight localities in SE Norway. It resembles C. polycarpoides morphologically, but differs in containing barbaric acid and chlorovinetorin.

The new species Rhizocarpon timdalii, is described from north-west Europe and north-east North America. The ecology and distribution of the new species are also discussed.

Menegazzia neotropica sp. nov. is described from upper montane forest remnants and paramos in Ecuador, Colombia and Venezuela. It is characterized by short-pedicellate apothecia with ridged margins that partly obscure the discs, and by narrow, glossy lobes with brown-black margins. Menegazzia dissecta is recorded from South America for the first time and M. terebrata is recorded from Colombia and Ecuador for the first time.

Porina fortunata P. M. McCarthy & Etayo sp. nov. (Trichotheliaceae) is described from shaded basalt in Gomera, Canary Islands. It is characterized by a richly rimose to areolate thallus, small, prominent and outwardly blackish perithecia that are internally orange-brown and narrow and elongate, 3(-7)-septate ascospores.

A key to forty-one species in ten parmelioid genera [Bulbothrix (4 spp.), Canoparmelia (1 sp.), Hypotrachyna (7 spp.), Myelochroa (1 sp.), Parmelina (2 spp.), Parmelinopsis (1 sp.), Parmotrema (18 spp.), Relicina (2 spp.), Rimelia (3 spp.) and Xanthoparmelia (2 spp.)] from New Caledonia is provided, in addition to brief taxonomic descriptions as well as notes on distribution. Five of the forty-one species are endemic to New Caledonia, and thirteen are new records for the island. Several old names used in the literature are clarified.

The following new species of Parmeliaceae are described from Africa: Xanthoparmelia bainskloofensis Elix & T. H. Nash, X. boyeri Elix, X. dubitella Elix, X. kleinswartbergensis Elix, X. lobuliferella Elix, X. malawiensis Elix, X. micromaculata Elix and X. waboomsbergensis Elix. The new combination Xanthoparmelia patula (Brusse) Elix is made and X. hypoleiella Elix, X. neoconspersa (Gyeln.) Hale, X. neocumberlandia T. H. Nash & Elix and X. sipmanii T. H. Nash & Elix are reported from Africa for the first time.

Apothecia from Usnea longissima thalli collected in the Oregon Coast Range are described. Fertile U. longissima specimens have seldom been observed and rarely documented in the literature. A brief history of accounts in the literature is given, and possible reasons for the infrequent occurrence of apothecia are discussed. This is the first published account of fertile U. longissima specimens in the U.S. Pacific Northwest.

The fruticose lichen Cavernularia hultenii exhibits a strongly disjunct distribution between north-western North America, Newfoundland and north-western Europe. An investigation of its population structure, based on nuclear ITS and IGS DNA sequences, shows that western North America has a higher number of haplotypes than the two other areas. Most of the haplotypes confined to this region are rare and occur outside the area that was affected by Pleistocene glaciations. Three haplotypes are common in all three areas. The high number of haplotypes in western North America might be due to a combination of events during the Pleistocene and Holocene epochs, viz. increased lineage survival by repeated fragmentation of populations and reduced lineage extinction through rapid postglacial expansion and population growth.

ITS rDNA sequence data shows that Diploicia and Diplotomma species form a monophyletic clade distinct from other Buellia species. This indicates that Diplotomma merits acceptance as a genus, and suggests that Diploicia should be treated as a synonym of Diplotomma, the earlier name. The data also shows Diploicia subcanescens, considered the fertile counterpart in a species pair with D. canescens, is nested within D. canescens and should be treated as a synonym despite reported chemical differences. In addition, the molecular data support the distinctness of Diplotomma rivas-martinezii, a species restricted to gypsum rocks in Spain, from the widespread D. venustum, which grows on calcareous rocks. Aposymbiotic cultures suggest that D. rivas-martinezii also differs from D. venustum in its germination and isolation success rates. One new combination is made: Diplotomnta pulverulenta (Anzi) D. Hawksw. (syn. Abrothallus pulverulentus Anzi) for the lichenicolous species previously known as Buellia pulverulenta.

A taxonomic revision of the lichen genus Gymnoderma Nyl. sensu Yoshimura & Sharp (Cladoniaceae) based on an integrative analysis of polyphasic characters supports the segregation of a new genus Cetradonia J.-C.Wei & Ahti in a new family Cetradoniaceae J.-C.Wei & Ahti. The monotypic genus and family are based on Cladonia linearis Evans. In addition, two species are recognized in genus Neophyllis F. Wilson and two species are retained in the genus Gymnoderma Nyl. of the Cladoniaceae.