The new generic name Bryobilimbia is proposed for Lecidea hypnorum and the closely related taxa Lecidea ahlesii var. ahlesii, L. ahlesii var. nemoralis, L. diapensiae, L. sanguineoatra and Mycobilimbia australis. A phylogenetic analysis based on five genes shows that Lecidea berengeriana does not belong to this group but is more closely related to Romjularia. Both groups of species have been included in Mycobilimbia by some authors but are instead shown to be most closely related to a group of genera (including Clauzadea, Farnoldia, Lecidoma and Romjularia) that do not belong to Lecideaceae s. str. A neotype is selected for Lichen sanguineoater Wulfen and the new combinations Bryobilimbia ahlesii var. ahlesii, B. ahlesii var. nemoralis, B. australis, B. diapensiae, B. hypnorum and B. sanguineoatra are proposed. A lectotype is also selected for L. templetonii Taylor.

The contact sites of pycnidia and the terminal cells of trichogynes in Cladonia furcata were investigated using either freshly fixed material, or ascomatal primordia and pycnidia from which the gelatinous material either on the primordial surface, or in the pycnidial cavity, had been removed. The sickle-shaped conidia fused, tip first, with the cell wall of trichogynes. Circular holes of about the diameter of the conidia found in the cell walls of trichogynes arise from enzymatic degradation of the wall material by fusing conidia. As the conidia appear to stick on any gelatinous surface material of the thallus the adhesion process is presumed to be unspecific.

A survey of epiphytic species on annual increments of Quercus petraea twigs in a west Wales woodland has shown that distribution of lichen species and rates of succession are affected by a range of environmental conditions. Lichen communities were recorded for 1–15 years on randomly sampled twigs along marked woodland boundaries affected by a range of climatic and management conditions. Results show that there is a correlation between environmental condition and lichen communities of twigs, and that indicator species can be used to detect trends towards acidification or eutrophication.

Ascus structure of eight yellow, two white and two brown Rhizocarpon species has been investigated by light microscopy. Ultrastructure and function in R. atroflavescens subsp. pulverulentum and R. montagnei were studied in TEM.

The Rhizocarpon-type ascus clearly differs from all other ascus types observed in the Lecanorales. It is bitunicate, opening with a slight ‘Jack-in-the-box’-mechanism. Its structure and function are related to patellariacean ascus types, but unlike those the ascus wall cytochemistry shows a certain similarity with Lecanora- and Peltigera-type asci. Rhizocarpon-type asci are embedded in a strongly amyloid hymenial gelatine. The nonamyloid ascus wall is surrounded by the strongly amyloid outer layer. The slightly amyloid expansible inner layer (= endoascus) is apically thickened; it shows the banded and pleated ‘accordion-structure’ characteristic of bitunicate asci. Prior to dehiscence, the ascus wall and its outer layer burst. Thereafter the pleatings of the expansible inner layer are stretched, forming the rather short beak which reaches the hymenial surface. During expansion gliding occurs between the expansible inner layer and an outer part of the endoascus, here described as the ‘inner layer’. In a few sections of aldehyde- fixed material of R. atroflavescens a small laminated plug was observed in the apex of the endoascus.

Rhizocarpon-lype asci are considered to be the most archaic in the Lecanorales. This supports a hypothesis that Rhizocarpon is a phylogenetically basal group, linking the evolved Lecanorineae, and possibly also the Peltigerineae and Teloschistineae with not yet recognized bitunicate ancestral forms similar to those occurring in the Patellariaceae.

Specimens of Dictyonema glabratum from various elevations in the Venezuelan Andes show clear differences in morphology. Optimal development of thalli is attained in the lower Paramo at 3500–3600 m; at the upper altitudinal limit of distribution at about 4300 m only poorly developed thalli are found; in the montane forest zone at about 1700 m the thalli attain about half the average surface area and two thirds of the thickness of those in the optimal habitat. The histological structure of the thalli also shows significant differences. The relative volumes of photobiont to mycobiont, as an indicator of the relationship autotrophism/heterotrophism, is 1.6:1 in specimens from the upper Paramo; 0.9:1 in open habitats on the lower Paramo; 0.5:1 in shaded habitats; and 1.4:1 in the montane forest. The three altitudinal morphotypes are not only distinguished by structure but also by carbon dioxide gaseous exchange patterns. Specimens from the optimal habitat exhibit the highest photosynthetic capacity. The respiration activity reflects a homeostatic adjustment to the prevailing temperature regime: the respiration of specimens from 4300 m at 1°C approximates to same intensity as that of D. glabratum from the lower Paramo zone at 6°C. Nevertheless, metabolic homeostasis is only possible over a narrow temperature amplitude. On account of the large heterotrophic component in lichens, at altitudes below 1500 m where the temperature average is 20°C or more and the nocturnal temperatures are constantly high, the dry matter consumption due to respiration would become extremely high. This suggests that D. glabratum may be limited in its downward distribution by an increasingly unfavourable carbon budget.

The phylogenetic position of the European crustose pioneer lichen Moelleropsis (Biatora) humida (Kullhem) Coppins & P. M. Jørg. is studied using partial sequences of the mitochondrial SSU and nuclear LSU rDNA of 64 ascomycetes, including sequences of all known species of Arctomiaceae. The analysis places M. humida in the Arctomiaceae with strong support as sister to the Tasmanian genus Wawea. The genus Arctomia is monophyletic and sister-group to the Wawea+Moelleropsis humida clade. The new genus Gregorella is described to accommodate Moelleropsis humida and the new combination Gregorella humida (Kullhem) Lumbsch is proposed. The ontogeny of the ascomata of Gregorella humida is similar to that of other Arctomiaceae, in that the generative tissue is formed on a thallus outgrowth. The Arctomiaceae did not cluster with the bulk of cyanobacterial lichens in the Lecanorales suborder Peltigerineae (or Peltigerales), but is part of Ostropomycetidae. The closest relative of Arctomiaceae could not be identified, since the relationships of major clades within Ostropomycetidae lacked support.

96 macrolichens, including 12 new records, are reported for cool temperate rainforests in Tasmania. These species belong mainly to the austral cool temperate element. A descriptive account of the lichen floras from five major rainforest communities is given. Field observations suggest that substrate and light are the most important ecological factors affecting the distribution of lichens in rainforest. Although most species are widespread in Tasmania, large-scale disturbance and the fragmentation of rainforest stands is seen as a threat to their survival.

Thirteen species of the lichen genus Sticta (Schreber) Ach., are recognized in the New Zealand flora viz.: S. babingtonii, S. caliginosa, S. colinii sp. nov., S. cinereoglauca, S. filix, S. fuliginosa, S. lacera, S. latifrons, S. limbata, S. martinii, S. squamata, S. subcaperata and S. sublimbata. A key to species, synonymy and typification, descriptions of all taxa, biogeographical affinities and distribution maps are presented. Sticta livida is excluded from the New Zealand flora.

The phylogenetic position of the genus Geisleria and its type species G. sychnogonioides was reconstructed using sequence data of the mitochondrial small subunit (mtSSU), the nuclear large subunit rDNA (nuLSU) and the first subunit of the RNA polymerase (RPB1). The species, previously classified in Verrucariaceae (Eurotiomycetes) and Strigulaceae (Dothideomycetes), is sister to the type of the genus Absconditella, A. sphagnorum, and nested within the genera Absconditella and Cryptodiscus combined (which also includes the lichenized Bryophagus). At first glance it appears to be a further example of parallel evolution of perithecioid ascomata within Stictidaceae (Lecanoromycetes: Ostropales), besides Ostropa and Robergea, adding to the growing list of perithecioid forms nested within apothecioid lineages in Ostropomycetidae, and specifically Ostropales, with other examples known from Graphidaceae (several genera), Gyalectaceae (Belonia), and Porinaceae. However, revision of type material collected by Nitschke revealed that the species actually develops typical apothecia with a narrowly exposed disc. We conclude that Geisleria sychnogonoides was erroneously considered a pyrenocarpous taxon, because in dry conditions the apothecia are closed and not recognizable as such. The species usually grows on unstable soil and therefore often only develops young, more or less closed ascomata (yet with mature ascospores), and has also been confused with the superficially similar Belonia incarnata, in which the ascomata remain closed even when mature. Geisleriasychnogonioides has so far only been known as a rarely reported pioneer species from loamy soils in Europe and North America. Here it is reported to occur abundantly on lateritic soils in subtropical Brazil, suggesting that it is cosmopolitan and possibly common, but much overlooked.

The following 24 new species of Trypetheliaceae are described after three weeks of fieldwork in an area with a radius of 50 km around Porto Velho in Rondônia: Astrothelium bivelum with astrothelioid ascomata, 5-septate ascospores with polar gelatinous caps, and a thallus without lichexanthone; A. curvisporum with bent, 5-septate ascospores of 115–135×29–36 μm with a 17–22 μm thick gelatinous layer; A. decemseptatum with pseudostroma that are essentially black and look like breaking through the bark, with anthraquinones mostly on the pseudostromata but also on some parts of the thallus, best seen under UV light as the colour of the pruina is not very strong, and ascospores (7–)9–11-septate, fusiform, 50–65×11–17 μm; A. disjunctum with black pseudostroma and ascospores 3-septate, (27–)29–33×(8–)12–14 μm; A. duplicatum which is similar to A. mesoduplex, but pseudostroma are only yellowish inside and ascospores 45–55×11–15 μm; A. eumultiseptatum which is similar to A. eustomum, but with 9–11-septate ascospores of 65–70×15–17 μm; A. eustomurale which is also similar to A. eustomum, but with submuriform ascospores of 37–45×15–19 μm; A. flavoduplex which is similar to A. mesoduplex, but with ascospores 110–350×20–27 μm and the thallus containing lichexanthone; A. flavomurisporum with deeply immersed ascomata with muriform ascospores of 165–200×28–35 μm, with a distinctly thickened central septum and yellow oil; A. flavostromatum which is close to A. aeneoides and mainly differs by the bullate thallus and the cream pseudostromata; A. flavum which is similar to A. aeneum, but differs in the contrast between the linear to reticulate yellow stromata and the unpigmented thallus, and the ascospores of 16–18×6–7 μm; A. mesoduplex which is similar to A. flavoduplex, but with ascospores 90–100×20–23 μm and a thallus without lichexanthone; A. nigrum with mostly conical black pseudostromata that contrast sharply with the thallus, superficially resembling Pyrenula infraleucotrypa; A. novemseptatum which is similar to A. eumultiseptatum, but without lichexanthone anywhere in the thallus or pseudostroma; A. ochroleucoides which is similar to A. corallinum, but with lichexanthone on the thallus and pseudostromata; A. octoseptatum which is similar to A. eumultiseptatum, but with the whole pseudostroma, not just the ostioles, containing lichexanthone, and ascospores somewhat asymmetrical, which is highlighted by the unusual dominant even number of septa (eight) and the asymmetrically placed central septum in the case of uneven septum numbers; A. quatuorseptatum which is similar to A. octoseptatum Aptroot & M. Cáceres, but without lichexanthone, ascospores somewhat asymmetrical, which is highlighted by the unusual dominant even number of septa (four) and the asymmetrically placed central septum in the case of uneven septum numbers; A. robustosporum with solitary ascomata with an eccentric ostiole, and ascospores 11–15-septate, 90–125×20–27 μm; A. solitarium which is similar to A. ceratinum (Fée) Aptroot & Lücking, but with ascospores 33–36×10–11 μm; A. stromatofluorescens which is close to A. phlyctaena, but with lichexanthone only on the pseudostroma, not on the thallus; A. supraclandestinum is close to A. subclandestinum, but the hamathecium is not inspersed; A. testudineum with solitary ascomata with an eccentric ostiole, an inspersed hamathecium, and ascospores 8 per ascus, muriform, 50–65×23–27 μm; A. xanthosuperbum which is similar to A. disjunctum, but with muriform ascospores, 130–160×28–35 μm; and Pseudopyrenula flavoreagens which is similar to P. subgregaria, but with lichexanthone in the thallus. Only a few species were also found elsewhere, such as other areas of Brazil, or in Venezuela, Colombia, Guyana, Panama, Australia and/or Papua New Guinea. Currently, 55 species of Trypetheliaceae are known from this spot, including 46 species of Astrothelium. The Amazon basin is the centre of diversity for the family, at least for Astrothelium, the largest genus in the family.

Notes and keys are provided for British members of the Trapeliaceae. The genus Placynthiella Gyelnik is resurrected to accommodate the Lecidea uliginosa group: P. hyporhoda (Th. Fr.) comb, nov., P. icmalea (Ach.) comb, nov., P. oligotropha (Laundon) comb. nov. and P. uliginosa (Schrader) comb. nov. Aphanopsis Nyl. ex P. Sydow is recognized for the single species A. coenosa (Ach.) comb, nov., and attention is drawn to the enigmatic Biatora humida Kullhem. The Lecidea granulosa group is referred to Trapeliopsis, necessitating four new combinations, T. aeneofusca (Flörke ex Flotow) comb, nov., T. flexuosa (Fr.) comb, nov., T. gelatinosa (Flörke) comb. nov. and T. viridescens (Schrader) comb, nov., and the description of one new species, T. pseudogranulosa sp. nov. Special attention is given to sorediate species of Trapelia, including T. corticola sp. nov. and T. placodioides sp. nov.

In order to identify monophyletic groups within the family Parmeliaceae, eleven taxa (Bryoria capillaris, Cetraria islandica, Evernia pruniastri, Hypogymnia physodes, Parmelia saxatilis, Platismatia glauca, Pleurosticta acetabulum, Usneaflorida, Vulpicida juniperina, V. pinastri, and Xanthoparmelia conspersa) were studied using newly produced nuclear rDNA sequence data from the ITS and 5·8S regions. The resulting evolutionary hypothesis was compared with results from previous phylogenetic analyses based on anatomy, morphology, and chemistry. The outcome of this comparison does not support the earlier proposed phylogenies but is not stable enough for identifying monophyletic groups, with one exception. The results indicate a close relationship between Cetraria and Vulpicida, which is contradictory to previous published analyses. The variation in ascus structures in the Parmeliaceae is discussed and it is questioned whether the earlier distinguished ‘ forms ’ of ascus types represent synapomorphies, if they are based on poorly supported analyses, or if they are exaggerations of relatively slight variation in shape. Further interpretations of the results are discussed and areas of future studies based on DNA-data are suggested.

This paper reassesses the European and Macaronesian species of Nephroma, analyses their chemistry, and provides a key to the 14 species accepted. The investigation employs chemical techniques which enable even fragmentary material to be identified. Seven chemical groupings are recognized in the genus of which four occur in the species discussed here. Particular emphasis is placed on the distribution of major hopane triterpenoids within the genus. N. areolatum, N. foliolatum, N. hensseniae and N. sulcatum spp. nov. are described from Macaronesia, and N. tangeriense (Maheu & A. Gillet) Zahlbr., is accepted as distinct.

The present occurrence and vitality of Lobaria scrobiculata (Scop.) DC. were investigated at 67 localities (50 old and 17 new) in southern Sweden. Before 1950 L. scrobiculata was found at more than 300 localities in southern Sweden. However, it was only confirmed at two out of 50 thoroughly investigated old localities. An investigation of recently found localities (new) and confirmed ‘old’ sites showed that there have been decreases in population size, thallus size, fertility, number of phorophytes, and cliff colonization. In southern Sweden today L. scrobiculata is confined to old deciduous trees in regions with comparatively low air pollution and a high relative humidity. Apothecia have not been found in southern Sweden since 1947, although in the past, fertile material was collected from 35 localities in this region. The author suggests that this species, like many other lichens with the cyanobacterium Nostoc as photobiont, is currently more endangered by air pollution than by any other human activity and that it is seriously endangered in the southern part of Sweden.