The new fungus Cercidospora alpina is described from Sweden where it grows on the thallus of the crustose lichen Stereocaulon cumulatum. The ecology and distribution of the new species as well as its morphological similarities to related species are discussed. A key to the known species of Cercidospora occurring in Fennoscandia is provided.

A new species, Caloplaca lenae Søchting & Figueras is described. It is a saxicolous lichen from a very dry and warm region of Central Asia, characterized by a thick occasionally effigurate thallus, with well-developed, labriform soralia, and conspicuous dark pycnidia. The apothecia are only present in some localities, and the spore form is very variable. Apart from anthraquinones it contains the depsidones, caloploicin, vicanicin and isofulgidin that have been recorded from few other species of Caloplaca, Fulgensia and Teloschistes. The taxonomic significance of the presence of depsidones is discussed in relation to a phylogenetic tree inferred from ITS data of nuclear ribosomal DNA.

Detailed studies on the lichen genus Porina in Macaronesia have led to a reappraisal of the genuine identity of Porina atlantica (Erichsen) P. M. Jørg., a characteristic species that has previously been confused with P. guaranitica, P. heterospora, P. nucula, P. mastoidea or P. rhodostoma in the literature, and is here reported from Madeira, the Canary Islands, Ireland, France and Portugal. Two new species are described: P. effilata Brand & Sérus. sp. nov. (known from Madeira, the Canary Islands, Great Britain, Ireland and Portugal) and P. ocoteae Brand & Sérus. sp. nov. (restricted to La Palma, Canary Islands, and São Jorge in the Azores). Porina leptospora Nyl. is recognized at the species level, and P. isidiata Kalb & Hafellner is reduced into synonymy with P. atlantica. A key to all known species of Porina in Macaronesia is provided.

Thelopsis paucispora is described as new from Socotra (Yemen, Indian Ocean). The species is characterized by asci containing 30–40, two-celled spores, Trentepohlia as photobiont and a crustose subeffigurate thallus colonizing calcareous rock. A key for all known species of the genus Thelopsis is provided.

Buellia peregrina is described as new to science from small limestone pebbles on exposed ground of the coastal Namib Desert, Namibia. The species is unusual for two reasons: (1) it is the only species in Buellia s.l. currently known to grow euendolithically, i.e., establishing a thallus entirely within its rock substratum, and (2) its apothecia contain a previously unknown blue pigment, here described as peregrina-blue according to its colour and characteristic reactions with HNO3, KOH and HCl.

One new species and 71 new records are reported from Thailand. Coenogonium disciforme sp. nov. is distinguished by its disc-shaped, shortly stipitate isidia, which leave perfectly circular holes, almost like punched holes, when detached.

A detailed chemical and morphological study has been carried out on West European specimens of Cladonia subulata (L.) F. H. Wigg. and C. rei Schaer. Using thin-layer chromatography (TLC), three different chemotypes were found, which did not show any correlation with distribution, substratum, habitat or any of the morphological characteristics mentioned in recent floras. Moreover, the application of UV (long-wave) proved to be unreliable for detecting homosekikaic acid and thus for distinguishing the two species. It appears that only one species, with three chemotypes, exists in Western Europe. Cladonia subulata is therefore another of the more than ten Cladonia species reported so far that can contain either homosekikaic and/or fumarprotocetraric acid.

In this investigation we utilized parsimony and Bayesian analyses of mtSSU and nuLSU rDNA sequence datasets to show that the lichenized ascomycete genera Leptochidium and Polychidium (formerly classified in Placynthiaceae) form a well-supported monophyletic group with Massalongia (Peltigerales, Lecanoromycetes, Ascomycota). This group is also supported by morphological characteristics (ascus type, ascoma ontogeny and anatomy), but does not have a formal name on any level. We describe it here as the family Massalongiaceae. Massalongiaceae is related to a group consisting of Peltigeraceae-Nephromataceae, and Lobariaceae, but the detailed relationships within this group are not resolved with convincing support.

Genetic diversity in symbionts of the lichen Cladonia arbuscula was investigated. Forty-eight specimens of Cladonia arbuscula located within a 2 km range at Payuk Lake in Manitoba were collected. Population structure and method of symbiont transmission in C. arbuscula were inferred by examining the presence or absence of introns in the nuclear small subunit (SSU) ribosomal DNA (rDNA) of the mycobiont and restriction fragment length polymorphism (RFLP) of the internal transcribed spacer (ITS) rDNA in the photobiont. The mycobiont showed a high level of genetic variation and the photobiont a low level of variation within the small geographic range studied. An analysis of molecular variance of fungal genotypes showed significant population subdivision for the mycobiont when the data were analysed at P=0·05. No population subdivision was detected when P=0·001. The photobiont also showed no population subdivision. Photobiont genotypes did not correlate with mycobiont genotypes suggesting the symbionts were not transmitted together in the same propagule. Multiple fungal genotypes were also detected in C. arbuscula and possible explanations were discussed.

The effect of a copper-smelting plant on populations of Hypogymnia physodes and Tuckermanopsis sepincola was studied in the Middle Urals. A different population response was found between the two lichen species due to different life strategies. The pollution appears to decrease growth and developmental rate of H. physodes (a vegetatively reproducing strongly competitive species), resulting in a shift of population structure towards smaller, esorediate to low sorediate thalli. The background population of the sexually reproducing Tuckermanopsis sepincola consisted mainly of young, small thalli of a low fertility as a result of strong inter-species competition with H. physodes. At the polluted site, the sharp decrease in the abundance of H. physodes led to a shift in structure of the T. sepincola population towards larger and more fertile thalli. It may be concluded that T. sepincola benefits from air pollution by an indirect effect of the removal of a strong competitor, i.e. H. physodes.

The effect of increasing concentrations (0·01, 0·1, 1 and 5 mg l−1) of intact (FLT) and photo-modified (phFLT) fluoranthene and the duration of exposure (1, 2, 3, 5 and 7 days) on the chlorophyll fluorescence parameters (F0, FV/FM, and ΦII) of symbiotic algae in the thalli of two foliose lichens Lasallia pustulata and Umbilicaria hirsuta was investigated. In addition the FLT concentration in thalli of both lichen species was determined and a bioconcentration factor (BCF) was calculated. The results obtained demonstrated that the concentrations of FLT and especially phFLT (1 and 5 mg l−1) applied affected primary photochemical processes of photosynthesis in the algae of both lichen species. The F0 value increased and the FV/FM and ΦII values decreased. The fluoranthene content in the thallus of both lichen species increased with increasing FLT concentration in the environment.