Lecanora paramerae is described from Central-East Spain. At the only two known localities it grows on Juniperus thurifera trees in the ‘Serranía de Cuenca’ mountains. It is chemically characterized by the presence of 2′-O-methylperlatolic acid in addition to atranorin and psoromic acid. Anatomically, it can be recognized by the presence of large and irregular crystals in the amphithecium, a pulicaris-type epihymenium and broadly ellipsoid ascospores.

The genus Biatora is still undercollected in many parts of its distributional range. On the basis of recent collections made by the authors and additional herbarium material not studied previously, more detailed statements on the ecology, distribution and conservational status of Biatora species in Central Europe are possible. Distribution maps are provided for B. fallax, B. mendax, B. ocelliformis, B. rufidula, B. sphaeroidiza, and B. vernalis. Biatora species are almost exclusively non-saxicolous and, in general, prefer humid habitats. Many species are chionophilous and extremely shade-tolerant. Three main distributional patterns can be observed: (sub-)arctic-alpine species, sub-oceanic-montane species, and species of montane coniferous or mixed coniferous forests. Biatora efflorescens, B. flavopunctata and B. subduplex are relatively frequent species and are not threatened. Biatora rufidula and B. vacciniicola must be regarded as extinct in Central Europe. The following species are reported for the first time from the respective countries: B. chrysantha from Romania, B. efflorescens from Romania and Ukraine, B. fallax from Austria and Ukraine, B. mendax from the Czech Republic, B. ocelliformis from Romania, and B. sphaeroidiza from Germany, Austria, the Czech Republic and Romania.

Porina otagensis P. M. McCarthy (Trichotheliaceae) is described from semi-aquatic rocks near Dunedin in the South Island of New Zealand. It has perithecia with a thin, applanate to convex, spreading involucrellum, rather short but broad, 7-septate ascospores that lack a gelatinous sheath, and comparatively broad conidia.

Two new species of Psoroma with unusual cephalodia are described: P. echinaceum with isidiate cephalodia, from southern South America and P. geminatum with fragile phyllidiate cephalodia, from New Zealand and Australia. These are additional to two previously described species producing dispersal units on their cephalodia, P. durietzii P.James & Henssen (with soredia) and P. aphthosum, Vain. (syn. nov. P. dimorphum Malme) (with isidia). This is a strategy development that ensures successful establishment of new thalli.

Porina pseudoapplanata Lücking & Cáceres sp.nov. is characterized by its foliicolous growth habit, a thin, nitidous thallus without crystals, applanate, yellowish red perithecia narrowly bacillar, 7-septate ascospores, and the presence of previously unrecognized isidi belonging to the Phyllophiale-type, here formally described as P. viridis Lücking & Cáceres sp.nov. The interpretation of Phyllophiale representing isidia of Porina species is discussed. Porina pseudoapplanata is similar to species in the P. rufula group, i.e. P. monocarpa (Kremp.) F. Schill., P. cupreola (Müll. Arg.) F. Schill., P. planiuscula Vêzda and, in particular, P. applanata Vain. However, it seems most closely related to P. mirabilis Lücking & Vězda in the P. epiphylla group, from which it differs by the complete absence of crystals in the thallus and perithecia. This gives a further insight into systematic relationships within the Trichotheliaceae. Keys are presented to distinguish P. pseudoapplanata from similar and related species, as well as to the known species of Phyllophiale.

This paper provides a revision of the foliicolous representatives of the Gyalectaceae in Costa Rica. Five species of Coenogonium and 13 of Dimerella are distinguished. Coenogonium interplexum, C. interpositum, C. leprieurii, C. linkii and Dimerella vezdana are ubiquitous as to the choice of their substratum, whereas C. moniliforme and Dimerella lutea are facultatively foliicolous. The remainder are typically foliicolous taxa but may occasionally be found on bark. The following species are for the first time reported as foliicolous from Costa Rica: Coenogonium interplexum, C. interpositum, C. leprieurii, C. moniliforme, Dimerella fallaciosa, D lisowskii, and D. aff. pilifera. Three new species are described: Dimerella isidiifera sp. nov. with disciform isidia, D. subzonatasp. nov. with small, bright yellow, dentate apothecia and a whitish prothallus, and D. siquirrensis sp. nov. with large, orange apothecia and a thin whitish prothallus. A key is presented for neotropical foliicolous Gyalectaceae, and notes on the distribution and ecology of the species are given.

The influence on uptake and water loss of the structural changes experienced by Parmelia acetabulum during thallus development were investigated. Small specimens were characterized by flat lobes and a thin thallus and cortex. Large specimens appeared strongly rugose, imbricate and irregularly folded, and had a significantly thicker cortex and medulla than small thalli. Maximum water storage capacity did not differ between large and small thalli, although water retention was much higher in large thalli, presumably due to the interaction of structural characteristics and a higher boundary layer resistance. This translated into a longer duration of the period of thallus hydration in large thalli compared to small thalli. Incubation of thalli in water-vapour-saturated atmospheres induced full recovery of photosynthetic electron transport to the values before desiccation in small thalli but only induced a partial recovery in large thalli. The close correlation between photosynthetic electron transport and net photosynthesis during desiccation found in this species suggested that carbon-fixation activity could be regained to a larger extent by incubation of thalli in water vapour in small compared to large thalli. The higher ability for water vapour uptake of small thalli might allow them to efficiently use small amounts of intermittently available water or periods of high relative humidity. The significance of this differential ability to utilize water is discussed with regard to the known ecological preferences of the species.

The post-fire colonization of a Quercus ilex forest by epiphytic lichens has been studied in Catalonia (NE Spain), eleven years after a fire. Specific richness and lichen biomass have been studied separately on Quercus ilex, Erica arborea, Rosmarinus officinalis. and Cistus albidus, to reveal possible differences among phorophytes in facilitating lichen establishment. Shrubs play an important role in colonization by common species whereas the stools of Quercus ilex offer a suitable substratum for rarer species. Cistus albidus, with the highest lichen diversity and 98·2% of the total biomass of macrolichens, is the most suitable phorophyte for lichen establishment.