A detailed taxonomic survey of the saxicolous European species of Buellia based on a detailed survey and assessment of the important features of the genus is presented. These include the conidia, the anatomy of the exciple, the spore wall pigmentation, ornamentation and internal wall thickening, as well as analysis of the lichen substances. As a result, 36 saxicolous species are recognized, of which Buellia griseosquamulata and B. longispora are new taxa and B. atrocinerella and B. parvula are new combinations. Buellia coniops, B. lecideina and B. punclata are transferred to the validated genus Amandinea. A key to 43 accepted species of Buellia, Amandinea and Hafellia is included.

Cladonia azorica is widespread in western Great Britain, mainly as the grey colour-form lacking usnic acid. Cladonia azorica is distinguished from the related species C. portentosa and C. mediterranea by the presence of fumarprotocetraric acid, and from C. ciliata by a number of characters including the presence of perlatolic acid. The structure of the pycnidial wall may have some taxonomic significance in Cladonia subgenus Cladin

Twenty species and one variety of the genus Bactrospora Massal. are revised. The following new species are described: B. arthonioides sp. nov., B. brodoi sp. nov., B. carneopallida sp. nov., B. incana sp. nov., B. intermedia sp. nov., and B. spiralis sp. nov. Six species of Lecanactis and one of Bacidia are transferred to Bactrospora. A key is given.

Twenty-two species of Ramalina are reported from Brazil. Their taxonomy is discussed and a key is provided. Ramalina denticulata var. stephanophora is reduced to synonymy with R. aspera, R. flagellifera with R. camptospora, R. denticulata var. subolivacea and R. complanata f. reagens with R. complanata, R. dendriscoidella and R. tenella with R. dendroides, and R. bicolor with R. gracilis. Ramalina asahinae, R. calcarata, R. pusiola, R. sorediosa, and R. sprengelii are new to Brazil.

The lichen Lecanora schistina (Nyl.) Arnold has two kinds of conidia: filiform microconidia and obpyriform macroconidia. Both appear mixed in the same conidioma, the former being much more abundant. Sometimes these conidiomata contain a third type of conidia (microconidia) belonging most probably to a lichenicolous coelomycete living in the conidiomata of the lichen.

The little known Porina schizospora Vainio is transferred to the genus Strigula as Strigula mediterranea Etayo nom. nov. Strigula mediterranea differs from S. taylorii only in its conidia and its Mediterranean distribution.

Phaeographina buxi is described from Buxus sempervirens to the south of the Pyrenees. It lives in canyons and geomorphologically similar habitats with a rich assemblage of epiphyllous lichens. The tropical genus Phaeographina is reported for the first time on the European continent.

A taxonomic revision of 15 taxa of Diploschistes from India and Nepal is presented. Two species, D. awasthii and D. nepalensis, are described as new. Diploschistes caesioplumbeus (Nyl.,) Vainio, D. diacapsis (Ach.) Lumbsch and D. eugatieus (Massal.) Steiner are new records for the lichen flora of India.

Laurera robusta McCarthy & Kantvilas sp. nov. (Trypetheliaceae) is described from alpine heathland in Tasmania. Anthracothecium monosporum Müll. Arg. is synonymous with L. elatior (Stirton) D. Galloway, while L. megasperma var. tasmanica (Jatta) Zahlbr. is referable to Pyrenula.

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.

The new lichen genus Musaespora is described from Java and Papua New Guinea. It is the first known pyrenocarpous lichen genus with campylidia, and appears to belong to the Aspidotheliaceae. Three species are described, two foliicolous species from Papua New Guinea and one corticolous species from Java. In addition, a list is given of the foliicolous lichen flora of the site in Papua New Guinea, where the foliicolous Musaespora species have been found, two more new foliicolous species are described, Echinoplaca hispida and Sporopodium lucidum, and 19 species are recorded for the first time form Papua New Guinea.

Four new species of Caloplaca are described from Antarctica: C. buelliae is parasitic on Buellia, C. iomma has a characteristic deep reddish orange colour on the apothecia, C. psoromatis is parasitic on Psoroma and Pannaria, and C. siphonospora is a parasitic species of mosses, very similar to C. nivalis, but with much shorter spores.

A new species, Everniastrum diffractaicum the only member of the genus containing diffractaic acid, is described. It has much larger ascospores than those of any other member of the genus.

Porina constrictospora sp. nov., P. decrescens sp. nov., P. hyperleptalea sp. nov. and P. sylvatica sp. nov. are described from western Tasmania. All appear to be especially common m cool-tempertate tamforest. A Key is provided to xhe six corticolous species of Porina known from Tasmania.

Thelidium austroatlanticum sp. nov. is described from Signy island; it is characterized by an epilithic thallus, more or less appressed involucrellum, and 1-septate spores 30–40 μm long. Thelidium incavatum is also reported for Signy Island.

Following a nationwide survey, the lichen vegetation associated with chalk grassland in England is described. The flora can be divided into species associated with flints (78 spp.), those found on chalk pebbles (65) and those occurring on the ground (72). Factors governing the distribution of the species were investigated. An important determinant of the flint assemblage is the degree of surface leaching, which is linked to stability; large flints embedded in turf are particularly rich. Chalkpebble lichens reach their maximum development at sites where faulting or other influences have hardened the substratum. Terricolous species have rather specialized requirements, being favoured by stresses associated with nutrient depletion, past disturbance, soil compaction, drought, rabbits, trampling by shoes (rather than hooves), and the presence of a small loess fraction in the soil. On both a national and a local scale, climate has been demonstrated to affect the distribution of certain species. Guidelines on the assessment of localities for conservation are provided and used to identify elite sites. A recent decline in the extent and species diversity of terricolous communities is giving cause for concern. Management requirements for conservation are discussed. They include recognizing the importance of intermittent disturbance; most of the richest sites are less than a hundred years old. The lichen flora has affinities with that present in urban areas. The survey provides an example of the importance of historical factors in determining the ecology of lichen communities in the cultural landscape.

A general account of the lichens of high-level acid habitats in the Lake District is provided. This is followed by detailed studies of base-rich sites in the Helvellyn range, acid outcrops in Langdale, and three upland tarns, one of which is of outstanding importance. The lichen vegetation is richer than in Snowdonia or the Northern Pennines, but its diversity is considerably less than that of certain individual mountains in the Scottish Highlands. The montane element is interpreted as representing the last remnants of communities that have declined gradually through the Postglacial Period. Many species are extremely rare. Current restraints on the alpine lichen flora include the climate, the predominance of wet, acid rock and heavy sheep grazing. Rhizocarpon simillimum is reported as new to the British lichen flora

Eleven stands of umbilicate lichens exhibiting a range of variabilities in enzyme banding patterns were compared on the basis of the ultraviolet (UV)absorbing properties of thallus extracts. Stands of Umbilicaria veilea, which were some of the most variable enzymatically, had the lowest UV absorbancy in extracts, and stands of Lasallia papulosa, which were among the least variable enzymatically, showed more UV absorbance than others. Umbilicaria deusta, U. muhlenbergii and U. mammulata had intermediate levels of absorbance. Negative correlations (P = 005–007) were found between enzyme polymorphism and UV absorbance in the ranges 215–220, 269–271 and 304–305 nm. There was also a significant negative correlation at P = 003 between enzyme variability and thallus dry weight extractable with either ethanol or acetone.

The new species Peltula sonorensis is described from the Sonoran Desert. It is found in several localities throughout the Mexican part of the Sonoran Desert and belongs to a distinct group within the genus Peltula, which is characterized by fairly large (up to 15 mm diam.), umbilicate-peltate squamules, growing individually and having ellipsoid to bacilliform spores.

High performance thin layer chromatography (HPTLC) is a method that can be used for screening lichen substances. It is as simple to use as standard TLC, but has many advantages: It is more sensitive, it is possible to run more samples in a shorter period of time, and the amount of solvent used is much smaller. The material needed and the methods used are described in detail. Horizontal chromatogram development was used. Since two of the solvents used in system B have been substituted, and since the properties of the HPTLC plates are slightly different, our results are not entirely in accordance with the standardized TLC method. A revised table for the identification of 69 lichen substances (obtained from 62 taxa) is accordingly presented.