The effects of hydrogen sulphide (H2S) on five lichens with different photobionts, ecology, and tolerance to the pollutant were studied by means of samples exposed in closed chambers containing two known H2S solutions. The H2S concentration in the void volume at equilibrium with the liquid phase was measured by gas chromatography-mass spectrometry, combined with the use of solid phase micro extraction (GC/MS SPME). It was determined as 8 and 28 ppm H2S in the absence of lichen material, and c. 2 and 10 ppm H2S respectively with living lichen material inserted for 8 hours in the exposure chambers. Significant differences in the species-specific emission of chlorophyll a fluorescence (ChlaF) were observed, with a pronounced depression of Fv/Fm already detectable after 2 h exposure at 28 ppm H2S in all the species. The decreased intensity was positively correlated to sample surface and, to a lesser extent, to the species-specific pre-exposure Fv/Fm value. Dark-exposed samples were less affected than light-exposed ones. All four chlorolichens could recover the pre-exposure ChlaF emission after two days in the absence of H2S, both in the light and in the dark, whereas the cyanolichen did not recover when kept in the dark. The results are thoroughly discussed on the basis of the known action mechanisms of H2S on the photosynthetic apparatus of vascular plants and cyanobacteria.

The activity concentration of 131I, 134Cs and 137Cs radionuclides in lichens was traced one and a half months after the Fukushima nuclear accident. The samples were collected in Tsukuba City, which is located c. 170 km south of the Fukushima Daiichi nuclear power plant (NPP). The activity concentrations differed depending on species and habitat. For example, the maximum activity concentration of 137Cs was 22596 Bq kg–1 dry weight in Physcia orientalis (collected from the trunk of Zelkova serrata on 30 June 2011), and 1928 Bq kg–1 in Hyperphyscia crocata (from the trunk of Quercus myrsinaefolia collected on 8 March 2012). The activity concentration of 137Cs in Dirinaria applanata and Phaeophyscia spinellosa growing on vertical habitats decreased by c. 50% within a year, indicating radionuclides might have been washed off by rain. The radionuclides were apparently derived from the Fukushima NPP accident because: 1) one specimen collected at the same place one year before the accident did not contain radionuclides, 2) high activity concentrations of radionuclides were detected after the accident, 3) 131I, which has a short half-life of 8 days, was detected one and a half months after the accident, and 4) the ratio of 134Cs/137Cs in lichens was 0·90–0·98 on 26 April 2011, which is consistent with the values reported for radiocesium from the Fukushima NPP accident.

Eurasian Cetraria steppae and the more widely distributed C. aculeata are two lichen species traditionally distinguished by Eastern European and Spanish lichenologists on the basis of their morphological and ecological characteristics. Other specialists, however, consider them puzzling. This paper aims to evaluate the taxonomic status of these members of the C. aculeata group and thereby to clarify their conservation status in Ukraine. Morphological, chemical and ecological features of specimens originating from populations in different regions of Ukraine were tested and compared with the main characteristics commonly used for the species delimitation. Neither morphological nor chemical traits were found to correlate with ecological characteristics on a small geographical scale. Variation in the norstictic acid content detected in 256 individuals from 13 populations in Ukraine showed no correlation with the morphological characteristics that are currently used for species delimitation. These morphological features appear to vary continuously and did not support subdivision among the specimens studied. We hypothesize that C. steppae and C. aculeata are conspecific, and provide a formal synonymy. Specimens with norstictic acid are regarded as a different chemotype. Possible evolutionary and adaptive roles of norstictic acid in C. aculeata s. lat. are discussed. Based on current and historical data, we consider C. aculeata s. lat. as vulnerable in Ukraine, according to the IUCN criteria for regional Red List assessment.

The new species Micarea corallothallina is described from Serra da Jibóia, Bahia, NE Brazil. It has a gnarled, coralloid, isidiose thallus and pale botryose apothecia. It was found in the Serra da Jibóia, a mountainous range with a maximum elevation of 800 m on smooth bark of trees. This Mata Atlantica fragment is located in the Santa Terezinha municipality, Bahia, NE Brazil, near the Castro Alves municipality boundary. This area can be considered as a rainforest enclave surrounded by Caatinga, and belongs to a disjunct set of mountains that extend from the southern coast of the state to the North-west and North.

Some lichens that occur in mountains and arid regions have developed an unusual anatomy resembling window-leaved plants. In these lichens, algal cells occur in thick vertical stacks (algal stacks) separated by vertical channels of light-transferring fungal hyphae (fungal stacks). We present experimental evidence that this anatomy permits higher rates of area-based CO2 assimilation in strong light, but that it also leads to higher respiration resulting in higher compensation irradiance. The net effect of this anatomy must be beneficial in regions of high insolation, as it has arisen many times in different parts of the world, and in unrelated lichens, and these lichens often dominate the communities in which they occur.

The new species Opegrapha subdictyospora is described from NE Brazil. It is only the third species in the genus with (sub)muriform ascospores and is further characterized by the brown pruinose discs. It was collected at Vale do Catimbau National Park in Pernambuco, which is a Caatinga area, where it is locally common.

The new species Byssoloma catillariosporum and Porina isidioambigua are described from NE Brazil. The first is reminiscent of B. leucoblepharum but differs by the consistently uniseptate ascospores. The second is characterized by tiny isidia and black perithecia with relatively large, 3-septate ascospores. Both species were found at the Área de Proteço Ambiental (APA) Morro do Urubu, an area of c. 214 hectares in the large (500 000 inhabitants) city of Aracaju. It is the only urban Mata Atlântica remnant in Aracaju, with mesophytic deciduous and semi-deciduous forest, and cerrado enclaves in isolated points.

Eumitrioid Usnea species are characterized by a tubular central axis throughout the entire thallus. Four species were identified in South America: Usnea baileyi is a (sub-) tropical species occurring both in continental South America and the Galapagos; U. perplectata has a scattered distribution worldwide and occurs in continental South America, mainly on the eastern range; U. flaveola and the newly described species U. subflaveola are both so far endemic to the Neotropical Andes. Distinct chemotypes, as well as anatomical characters, such as the thickness ratio of the medulla or the presence of medullar pigmentation, are diagnostic in delimiting these species. A detailed description of the species is provided together with an identification key.