Certain lichen epiphytes are restricted to old-growth forest stands with long ‘ecological continuity’, explained by i) niche specialism and their dependence on microhabitats associated with old stands including veteran or senescent trees, and/or ii) dispersal limitation with probabilities of colonization being relaxed over extended time periods. ‘Calicioid’ species are among the most important old-growth indicators, yet they reproduce sexually via small spores that appear widely dispersed at ecological scales. This suggests that they should have a high level of niche specialism compared to lichen epiphytes in general, explaining their role as old-growth indicators. However, comparisons of niche specialism are challenging, and this study uses epiphytic, corticolous calicioid species as an appropriate test case. Having measured 20 variables that constrain the lichen epiphyte niche, these were collapsed into a ‘hypervolume’ representing the sampled environmental space available for occupancy by lichens in Scotland as a study system. It was then possible to examine the occupancy of this hypervolume by individual lichens (niche breadth), with the proportion/percent occupied used to estimate a niche specialism score. Consequently, epiphyte calicioid species are confirmed to have a high degree of niche specialism compared to lichen epiphytes in general, and compared to other old-growth indicators, with their niche position directed towards drier climates including locally sheltered microhabitats associated with old-growth forest structure.

A brief discussion of the Encyclopedia of Life and the LifeDesks websites as a means to assemble and publish species pages and taxonomic information on the internet, for both the scientific community and the public, is provided. The lichen family Parmeliaceae is the first large group of lichenized fungi for which a concerted effort is currently being undertaken to produce substantial content for the EOL.

Three species of Porina (Trichotheliaceae), P.kansriae P. M. McCarthy, P. siamensis P. M. McCarthy and P. wolseleyae P. M. McCarthy, are described from aquatic and semi-aquatic rocks in montane rainforest in north-eastern Thailand.

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.

Two species of Catinaria with an unusual hepaticolous (i.e. growing on liverworts) lifestyle are described as new to science. Catinaria brodoana is described from species of Cheilolejeunea sect. Leucolejeunea (Lejeuneaceae) growing in south-eastern North America. Catinaria radulae is described from Radula flavifolia (Radulaceae) growing in the Cape Horn Archipelago of southernmost Chile, South America. The species are compared with the type of Catinaria (C. atropurpurea). In addition to occurring on hepatics, C. brodoana is characterized by its cellular exciple, warted ascospores and thallus composed of goniocysts, while C. radulae is characterized by its exciple of radiating hyphae, warted ascospores and absence of a lichenized thallus.

Pertusaria etayoi, found on lava flows and basaltic rocks from the Canary Islands, is described as new to science. It is the only species in the group of saxicolous Pertusaria with verruciform apothecia and 2 rough-walled ascospores to contain thiophaninic acid. A description of the species is given together with notes on its chemistry, distribution, ecology and taxonomy. Possible related lichen taxa are discussed briefly.

Skomer Island, a National Nature Reserve, lies off the West coast of Wales. This small island holds lichen communities of international importance associated with large populations of seabirds. Saxicolous lichen communities are described, 248 species listed and details given of a base-line monitoring programme, which will provide data on changes in the lichen flora over time and distinguish cyclical from permanent deleterious changes. Threats to island populations are discussed, such as the likely effects of oil pollution following the Sea Empress accident in February 1996.

Since the advent of molecular taxonomy, numerous lichen-forming fungi with homoiomerous thalli initially classified in the family Collemataceae Zenker have been transferred to other families, highlighting the extent of morphological convergence within Lecanoromycetes O. E. Erikss. & Winka. While the higher level classification of these fungi might be clarified by such transfers, numerous specific and generic classifications remain to be addressed. We examined the relationships within the broadly circumscribed genus Arctomia Th. Fr., which has been the recipient of several transfers from Collemataceae. We demonstrated that Arctomia insignis (P. M. Jørg. & Tønsberg) Ertz does not belong to Arctomia s. str. but forms a strong monophyletic group with Gabura fascicularis (L.) P. M. Jørg. We also confirmed that Arctomia borbonica Magain & Sérus. and the closely related Arctomia insignis represent two species. We formally transferred A. insignis and A. borbonica to the genus Gabura Adans. and introduced two new combinations: Gabura insignis and Gabura borbonica. We reported Gabura insignis from Europe (Scotland and Ireland) for the first time. While material from Europe and North America is genetically almost identical, specimens from Madagascar, South Africa and Reunion Island belong to three distinct phylogenetic lineages, all of which are present in the latter area and may represent distinct species. In its current circumscription, the genus Gabura may contain up to six species, whereas Arctomia s. str. includes only two species (A. delicatula Th. Fr. and A. teretiuscula P. M. Jørg.). The Gabura insignis group is shown to have an unexpectedly large, subcosmopolitan distribution. With the extended sampling from Arctomiaceae Th. Fr., the placement of Steinera sorediata P. James & Henssen in the genus Steinera Zahlbr. is confirmed and the presence of a new Steinera species from Chile is highlighted.

Nimisia fuegiae Kärnef. & Thell gen. et sp. nov. is described from Argentinian Tierra del Fuego. The new lichen differs from possibly related groups within the Parmeliaceae in unique anatomical characters, i.e. a medullary layer composed of extremely thick and strongly gelatinized periclinally arranged hyphae and a lower cortex composed of only a few layers of strongly pigmented, rather large cells. Ascus characters support its position in the Parmeliaceae. The new genus, which is named in the honour of its first discoverer, is discussed in relation to several other well-investigated members of the family.

Descriptions, illustrations, discussion and an identification key are presented for six saxicolous and terricolous species of the lichen genus Bacidia De Not. occurring in temperate Australia and Tasmania. Three species are described as new to science: B. lithophila Kantvilas from northern Tasmania, characterized by having only brown apothecial pigments and 3–5-septate, acicular ascospores, 23–35×1·5–2·0 µm; B. littoralis Kantvilas from Tasmania, South Australia (Kangaroo Island) and New South Wales, characterized by green and brown apothecial pigments and acicular, 3–7-septate ascospores, 24–48×2·0–3·5 µm; and B. maccarthyi Kantvilas from New South Wales, with pruinose apothecia and long, filiform, 17–25-septate ascospores, 65–115×2·5–4·0 µm. Three further species are reported for the region for the first time: B. bagliettoana (A. Massal. & de Not.) Jatta (Tasmania), B. curvispora Coppins & Fryday (Tasmania) and B. scopulicola (Nyl.) A. L. Sm. (Tasmania, Victoria).

Ten parmelioid taxa in five genera were identified from Rarotonga, Cook Islands, South Pacific Ocean. These comprise: three species of Bulbothrix, one species of Canoparmelia, four species of Parmotrema, one species of Rimelia and one species of Xanthoparmelia. Canoparmelia rarotongensis Louwhoff & Elix is described as new, being distinguished from other species of this genus by its unique secondary chemistry (lecanoric acid) and conspicuous, inflated isidia. The majority of parmelioid lichens on Rarotonga have cosmopolitan and pantropical distributions. Bulboihrix is reported for the first time from the Polynesian region.

The stages of vegetation development close to two glacier fronts on two of the South Shetland Islands (Livingston and Robert) within the Maritime Antarctic were studied with special reference to saxicolous lichens. A lichenometric study of the crustose lichen Caloplaca sublobulata was carried out at both sites. On the moraine of Livingston Island, rock size played an important role in lichen development, explaining most of the differences observed in the diameter of C. sublobulata, the number of species, and the percentage of cover among the rocks studied. On Robert Island, the distance from the glacier front was associated with the lichen cover of the rocks but not with diameter of C. sublobulata This homogeneous distribution of C. sublobulata thallus size on the Robert Island study area points to a simultaneous recolonization of the whole zone by this lichen. The lichen development in the area studied on Robert Island seems to have been drastically affected by fluctuations in the persistence of snow cover following glacier front retreat. Tentative associations between ice retreat and colonization, on the o e hand, and changes in snow cover duration and the dynamic processes of extinction and recolonization, on the other, are suggested from comparison of the two zones.

The taxonomy of the foliicolous members of Arthoniaceae (Anhonia, Arthothelium, Cryptothecia, Eremothecella) in Costa Rica is revised. Cryptothecia farkasiae sp. nov. is described, being closely related to Stirtonia sprucei, and bearing pycnidia reminiscent of Eremothecella. Anhonia lividofusca is placed in synonymy with A. aciniformis. Pycnidia and pycnospores are further described for Anhonialeptosperma, A. cyanea, A. palmulacea, A. trilocularis, Anhothelium cingulatum, Stinonia sprucei and S. macrocephala, and campylidia were found on thalli of Anhonia aciniformis. Anhonia nigratula and Cryptothecia Candida are reported for the first time from Costa Rica, and new localities are given for previously reported species. Ecological data are provided, and the relationships between foliicolous members of the Arthoniaceae are discussed.

Three new maritime saxicolous Ramalina species are described from Australia, R. litorea, R. whinrayii and R. caespitella N. Stevens spp. nov. The first species is tropical in occurrence, whereas the last two are temperate taxa and endemic to Australia.