The genus Japewia Tønsb. is introduced to accommodate three species including J. subaurifera Muhr & Tønsb. sp. nov. based on material from Norway, Sweden, Finland, Scotland, Canada (British Columbia) and U.S.A. (Washington). This species is closely related to Lecidea tornoensis Nyl. but is distinguished in being sorediate and by the production of lobaric acid (accessory) and acetone-soluble pigments. It grows on bark of deciduous and coniferous trees. Lecidea carrollii Coppins & P. James and L. tornoensis Nyl. are transferred to Japewia.

The genus Pterygiopsis Vainio (Lichinaceae), originally described from Brazil, is shown to have two species in Northern Europe: P. coracodiza (Nyl.) Henssen growing on irrigated rocks in N.W. Europe (France, Great Britain, W. Sweden and Norway), and P. lacustris P. M. Jørg. & R. Sant. sp. nov. occurring ± submerged in some lakes in S. Sweden.

A second species of the lichen-forming hyphomycete genus Cheiromycina B. Sutton, C. petri D. Hawksw. & Poelt sp.nov., is described from old Betula bark in Steiermark, Austria. It differs from C. flabelliformis B. Sutton in thallus colour, the more compact blue-grey non-eroding sporodochia, the very tightly dichotomously branched conidia, and in having much shorter terminal branches.

Lecanora creatina Norman ex Th. Fr. and Lecanora leucophyma Leighton were found to be synonyms of Koerberiella wimmeriana (Körber) B. Stein; both represents the isidiate growth form of the species. The lichenicolous fungi Arthonia almquistii Vainio, Endococcus propinquus (Körber) D. Hawksw. and Sagediopsis aquatica (B. Stein) Triebel occurs on K. wimmeriana. All are described in detail.

Ramalina erosa Krog, R. jamesii Krog, R. portosantana Krog, and R. timdaliana Krog are described as new from Porto Santo, Madeira. All four species are saxicolous and occur at or below c. 500 m alt. They are believed to belong in the Macaronesian endemic element.

The monotypic lichen genus Waynea gen. nov. in the family Bacidiaceae is described with the new species W. californica sp. nov. as type. It is known only from a few localities in California.

Thermutopsis jamesii Henssen gen. et sp. nov. (Lichinaceae) is described from calcareous rocks in Antigua. The new species resembles in habit Thermutis velutina but differs in the internal stucture and development of thallus and fructifications. The cyanobiont is a poorly lichenized species of Tolypothrix; the fructifications arise within the the gelatinous sheath of the algal filaments. The ascocarps are thallinocarps of a special type; the hymenium stains deep blue in iodine; young paraphyses are thick and richly branched; the prototunicate, non-amyloid asci contain 8 simple, colourless spores. The pycnidia are ellipsoid, producing small rod-shaped, acrogenous conidia.

Cladonia friabilis Ahti (type from Bahia, Brazil), C. pulviniformis Ahti (type from Bolivar, Venezuela), C. sufflata Ahti (type from Bolivar, Venezuela), and C. variegata Ahti (type from Bolivar, Venezuela) are described as new. Their major secondary metabolites are reported.

Three new species of Relicina are described: R. clarkensis Elix & Johnston and R. subcoronata Elix & Johnston from Australia, and R. columnaria Elix & Johnston from Papua New Guinea and Sabah.

Four new species of Micarea are described from Tasmanian collections: M. austroternaria sp. nov. (also from Chile), M. flagellispora sp. nov. (also from New Zealand), M. isabellina sp. nov., and M. mutabilis sp. nov. (also from mainland Australia).

The genus Pertusaria is a conspicuous component of the Tasmanian rainforest lichen flora and is represented by five species: P. gibberosa Müll.Arg., P. gymnospora sp. nov., P. jamesii sp. nov., P. novaezelandiae Szatala and P. truncata Krempelh. Pertusaria nothofagi Zahlbr. is added to the synonymy of P. truncata. Descriptive, ecological and distributional data for each species are provided.

The generic name Globosphaeria D. Hawksw. gen. nov. is introduced for the single species G. jamesii D. Hawksw. sp. nov. discovered on squamules of the lichen Normandina pulchella (Borrer) Nyl. collected in Tasmania. It is commensalistic or perhaps mutualistic. The genus is characterized by dark perithecioid ascomata, filiform paraphyses, thin-walled asci, and uniseriate thick-walled globose hyaline ascospores. It cannot easily be accommodated in any accepted order, and is tentatively referred to the Xylariales pending the discovery of fresh material.

Thirteen isidiate taxa in the Teloschistales are briefly discussed, i.e. Letrouitia corallina (Müll. Arg.) Hafellner, L. leprolyta (Nyl.) Hafellner, Caloplaca bassiae (Ach.) Zahlbr., C. granulosa (Müll. Arg.) Jatta, C. herbidella (Hue) H. Magn., C. isidiigera Vězda, C. isidiosa (Vainio) Zahlbr., C. littorea Tavares, C. namibensis Kärnef., C. ochraceofulva (Müll. Arg.) Jatta, C. verruculifera (Vainio) Zahlbr., Xanthoria domogledensis Veˇzda and X. isidioidea (Beltr.) Szat. The presumed origins and affinities of these taxa, which are also often fertile, are discussed. The role of isidia in reproduction and dispersal, and the justification of specific status in some of these taxa is questioned.

The question of whether or not some Trebouxia species have multinucleate cells is a controversial one. Trebouxia jamesii was re-examined and found to have multinucleate cells in cultures grown on rich, organic media. Possible reasons for this condition are discussed.

The annual rate of lichen decomposition was measured in a mixed, cool temperate rainforest in Puyehue National Park, southern Chile. Five macrolichens, Pseudocyphellaria berberina, P. divutsa, P. glabra, P. nitida and Sticta hypochra, and bamboo leaves (Chusquaea macrostachya) were used as experimental material. Rates of decomposition are high in all lichen species and ranged from k = 0·45 to 2·79. Lichens with hopane triterpenoids {P. divulsa and P. glabra) were more resistant to decomposition. The contribution of these lichens to the nutrient economy of the rainforest ecosystem is highly significant, as they are both abundant in terms of biomass and have a rapid turnover.

Lichens epiphytic on olive trees were used as biomonitors of sulphur dioxide pollution in La Spezia (Northern Italy). The method adopted was designed to avoid subjectivity at all stages, from the sampling strategy to data analysis. Thus, lichen data are expressed by an index that does not depend on any sensitivity scale; data analysis relies on multivariate methods of classification and ordination, and the pollution maps have been produced by automatic mapping programmes. The index, based on the frequency of species within a sampling grid, showed a very high statistical correlation with pollution data measured by recording gauges. The results of classification and ordination indicate that Parmelia caperata is the species with a distribution best related to the lichen index. The quality of air pollution data obtained from biomonitors is discussed.

The localization of psoromic acid and copper in partly green, copper-rich specimens of Lecidella bullata and Tephromela testaceoatra collected in Norway was studied by optical microscopy, scanning electron microscopy, and electron probe microanalysis. Infrared absorption spectroscopy of lichen material and of a synthetic copper-psoromic acid complex, and the other techniques, provide evidence that complexing of copper by psoromic acid occurs within specific areas of these lichens and this leads to their unusual colouration. In contrast, a specimen of copper-rich Lecanora cascadensis, which contains psoromic and usnic acids, does not contain such a complex. From the evidence obtained it is suggested that taxonomists should pay attention to the impact of rock and lichen chemistry on the appearance of lichen thalli.