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.