The effects of wave exposure and aspect on the zonation of supralittoral lichens were studied at 14 sites in Hong Kong. In general, increasing wave exposure raised the supralittoral zones and extended their vertical widths. A higher lichen cover in the lower zones (Zones 1 and 2)l was found with greater wave exposures, but the opposite was true for upper zones (Zones 3 and 4). Lichen diversity was greater with increased wave exposure in three out of the four zones (Zones 2–4). The effects of aspect are mainly due to the prevailing winds, which resulted in south- and east-facing shores supporting a higher cover and diversity of lichens. The distribution patterns of lichens on this subtropical seashore differed from previous studies in the temperate regions of the northern hemisphere.

Nylon mesh litter bags containing Parmelia caperata, P. flaventior, P. subrudecta, Evernia nesomorpha, Hypogymnia physodes and Umbilicaria muehlenbergii were placed on the floor of a black spruce bog in northern Minnesota to study the rates of decomposition. P. caperata and E. mesomorpha had decomposed after 10 months. Most of the lichens had completely decayed after 13 months but a few thalli of some species placed on top of hummocks were still alive. The species with usnic acid decayed as rapidly as those without. Lichens decompose rapidly but not more rapidly than some vascular plants.

The cyanobiont (Nostoc) of the lichen Peltigera horizontalis was isolated using a procedure of repeated grinding, differential centrifugation and partitioning in an aqueous two-phase system of dextran/polyethylene glycol. A yield of 22% was calculated on the basis of chlorophyll recovery from the thallus. Freshly isolated Nostoc differed little from that kept in prolonged culture with respect to the relative activities of a number of enzymes of carbohydrate metabolism in the soluble fraction. However, much higher specific activities of the disproportionating transglycosylase and starch phosphorylase, higher intracellular concentrations of glucose, maltooligosaccharides and glycogen and a lower rate of glucose uptake were evidentin freshly isolated Nostoc. These activities and pool sizes, as well as CO2-fixation capability, stayed roughly constant for at least 5 h after isolation; glucose release, which is characteristic for the symbiotic Nostoc, dropped sharply within 1 h. These observations suggest the transport of glucose out of the cell, rather than that theactivities of cytoplasmic enzymes may bea point of early regulation during transition of Nostoc from the lichenized to the free-livingstate.

The morphology, anatomy, chemistry, habitat and distribution of eight southern-Huropean sorediate, blastidiate or isidiate species of the genus Rinodina are treated. One species, R. nimisii, from Corsica and Sardinia, is new to science. Rinodina erysiphaea, R. sorediata and R. sipmanii are synonyms of R. colobinoides. A key is provided. Other known sorediate, blastidiate or isidiate species arc briefly discussed.

The new species Micarea usneae is described from Madeira. It has been found at two localities where it grew on epiphytic Usnea thalli. Micarea usneae is distinguished by a very thin pale brownish thallus, pallid to greyish black or bluish subglobose apothecia of 0·1–0·3 mm diameter, very narrow (1·5–2·5 µm) ascospores, black pycnidia and strongly curved to sigmoid macroconidia. Phylogenetic analyses using mtSSU sequences place the new species in the Micarea peliocarpa group. Catillaria usneicola and Cladonia parasitica are recorded for the first time from Madeira. A key to the lichenicolous species on Usnea in Macaronesia is provided.

Trapelia is a small genus of worldwide distribution. Trapelia coarctata has long been regarded as a morphologically variable species and phylogenetic studies have suggested that it is non-monophyletic, or at least that species are frequently misidentified. The phylogenetic relationships of freshly-collected material of Trapelia were studied using ITS, mitochondrial SSU rDNA and to a small extent also beta-tubulin sequence data, together with chemical and morphological characters. Sequence data combined with morphology and chemistry confirm that the diversity of the genus at species-level has been underestimated. Trapelia coarctata is defined in a more restricted way and many specimens previously referable to this taxon are assigned to the reinstated species T. elacista, which differs in subtle morphological characters including a crack separating the thallus and apothecium in well-developed thalli. Trapelia involuta is reinstated as a separate, though closely related, species to T. glebulosa based on sequence data, morphology and chemistry, and is lectotypified. Trapelia collaris is a distinctive species described as new from Great Britain which has an extensive, cracked thallus with abruptly thickening marginal areoles arising on an inconspicuous prothallus, relatively small apothecia (rarely exceeding 300 µm diameter) and contains 5-O-methylhiascic acid as the major secondary substance. Trapelia obtegens is shown to include frequent non-sorediate morphs which have doubtless been misidentified as other species. The number of species of Trapelia considered to occur in Europe is thus raised from five to eight. The genus is newly reported for the Falkland Islands where seven species occur: T. coarctata, T. placodioides, T. sitiens sp. nov. (with a thin, extensive thallus, sessile apothecia, 5-O-methylhiascic acid as the major secondary substance and the presence of conidiomata), T. tristis sp. nov. (with relatively small apothecia up to 460 µm diameter, presence of gyrophoric acid as the major substance and an absence of conidiomata) and three unidentified species represented by very sparse material. All the species studied, with the possible exception of the three unidentified species, can usually be distinguished by morphological features, particularly the method of development of the thallus and the shape and distribution of the areoles, but morphological variation in response to microhabitat variation is likely to make a proportion of specimens difficult to assign to species in the absence of sequence data.

Two Psoroma species, P. calophyllum and P. contortum, described from southern South America have been studied. The morphology, anatomy and chemistry of the two species are described together with notes on their ecology and taxonomy. The placing of these taxa in Pannaria is discussed, and the new combinations Pannaria calophylla and Pannaria contorta are proposed.

One new species and 71 new records are reported from Thailand. Coenogonium disciforme sp. nov. is distinguished by its disc-shaped, shortly stipitate isidia, which leave perfectly circular holes, almost like punched holes, when detached.

The lichen symbiosis has evolved several times within the fungal kingdom, although the total number of lichenization events leading to extant taxa is still unclear. Two lichenized families, the Icmadophilaceae and Baeomycetaceae have been classified in the Helotiales. Because the Helotiales are predominantly nonlichenized, this suggests that these families represent independent evolutionary episodes of lichenization from the Lecanorales. As a first step towards understanding the evolution of the lichen symbiosis within this order, we tested recent hypotheses concerning the segregation of lichen genera between the two lichen families. Specifically, we used phylogenetic analyses of nucleotide sequence data from nuclear small-subunit and large-subunit ribosomal DNA to test the morphology-based hypotheses that Dibaeis is a distinct genus from Baeomyces and that Dibaeis is a member of the Icmadophilaceae rather than the Baeomycetaceae. Phylogenetic analyses of nuclear SSU rDNA and combined SSU and LSU rDNA data support the hypothesis that Dibaeis is more closely related to IcmadophUa than it is to Baeomyces. Therefore, these data support the resurrection of Dibaeis from its previous synonymy with Baeomyces based on the characters of ascocarp colour and ascus morphology. The recognition of two distinct genera is also consistent with character state distribution of unique lichen acids.

Bird colonies affect all elements of inhabited ecosystems, such as the soil, floristic composition and phytocoenosis structure, including the lichen biota. To date, the few papers focusing on changes in the composition of lichen vegetation caused by bird colonies are concerned with saxicolous ornithocoprophilous communities. The aim of this study was to define the impact of the grey heron in two breeding colonies on epiphytic lichens on Scots pines presently inhabited by birds, as well as those recently abandoned. Analysis of the lichen biota showed that the species composition and number of lichens were significantly modified in the functioning colony and the post-colony areas when compared with the control plots never inhabited by grey heron. Within the functioning and post-colony areas, mainly species with a wide ecological amplitude and those characteristic of fertile habitats dominated, while acidophilous and ubiquitous taxa occurred in the control plots. Multivariate analyses (for species abundance and ecological characteristics) showed that lichens growing within the functioning colony and post-colony areas differed significantly from those in the control area in their habitat requirements, as they demanded nutrient-rich, low or moderately moist and deacidified bark. Within the control plots, lichens preferring a relatively acidic and slightly nitrified substratum occurred. The direct impact of bird excrement and the fertilized bark could cause significant modifications in qualitative and quantitative species composition compared to the epiphytic lichen biota usually occurring on Scots pines.

A new species, Caloplaca lenae Søchting & Figueras is described. It is a saxicolous lichen from a very dry and warm region of Central Asia, characterized by a thick occasionally effigurate thallus, with well-developed, labriform soralia, and conspicuous dark pycnidia. The apothecia are only present in some localities, and the spore form is very variable. Apart from anthraquinones it contains the depsidones, caloploicin, vicanicin and isofulgidin that have been recorded from few other species of Caloplaca, Fulgensia and Teloschistes. The taxonomic significance of the presence of depsidones is discussed in relation to a phylogenetic tree inferred from ITS data of nuclear ribosomal DNA.

Lichens are troublesome organisms for taxonomists because of their special ‘ double nature ’ i.e. being composed (normally) of two partners. Only recently has it been understood properly that the same fungus can take different photosynthetic partners and develop into quite different-looking organisms, for example Lobaria amplissima and Dendriscocaulon umhausense. The taxonomic problem is to show that two totally different-looking lichens in fact contain the same fungus. This is possible to demonstrate when mixed stands are available, but is now best done with molecular methods. Since the international code of nomenclature rules that the name of a lichen species is the name of the fungus, two different organisms with the same fungus must under the Code carry the same name, which is most impractical. To remove this unintentional complication, one must either make an exception in the Code for these cases, or establish an informal system to take care of them. The latter seems to be preferable.

The lichen vegetation associated with areas of late snow-lie in the Scottish Highlands is described and three lichen-dominated communities recognized; from the tops of large boulders, from small pebbles, and from damp soil. The first of these is exclusive to this habitat throughout the Highlands, whereas the other two are restricted to areas of late snow-lie in the Eastern Highlands but are of more widespread occurrence further west. The community from damp soil has affinities with the Solorinion croceae Klement, which occupies a similar ecological niche in Central Europe, but the two other communities are apparently undescribed. The importance of the eu-oceanic climate of the Western Highlands in determining the distribution of these communities is emphasized. The new combination Micarea cinerea f. tenuispora (D. Hawksw. & Poelt) Fryday is made for the anamorph of M. cinerea (Schaer.) Hedl.

The morphology, anatomy, chemistry and ecology of some corticolous and lignicolous species of Buellia from the Iberian Peninsula that contain secondary lichen compounds are discussed, including B. chloroleuca, B. disciformis, B. erubescens, B. hyperbolica and B. leptoclinoides. These species are compared with other corticolous Buellia species that occur outside the study area, including B. arnoldii, B. insignis, B. regularis and B. sanguinolenta. The misunderstood B. zahlbruckneri J. Steiner and B. jorgei, are synonyms of B. erubescens, and the invalid taxon B. zahlbruckneri sensu Schauer non Steiner and B. poeltii, are synonyms of B. chloroleuca. New chemical data on several taxa are reported. A key to the pecies and illustrations of their ascospores are provided.

Two corticolous species of the lichen genus Xanthoria, X. alfredi S. Kondratyuk & Poelt from Russian and Chinese Far East and X. aphrodites Kalb, Poelt & S. Kondratyuk from Cyprus are described. Morphological characters, in particular the presence of true rhizines within Xanthoria and their differences from hapters are indicated. Xanthoria novozelandica Hillmann is the first species of Xanthoria in which oil paraphyses have been found. A key to the treated species, including X. novozelandica and Xanthoria sp. from western North America is provided. The ecology and distribution of described species are discussed. Xanthoria alfredi and X. ulophyllodes probably constitute a typical species pair; X. alfredi and X. aphrodites are relict endemics.

The Parmelia saxatilis aggregate is comprised of three species in Europe, proposed to differ in morphological, distributional or chemical characters. In this study, we sampled nearly 200 thalli from five sites across a steep ecological gradient in Scotland to investigate the distribution of the species in the aggregate, and we characterized all specimens by morphological, chemical and ITS sequence variation. In our sample, 191 specimens were identified to species using ITS. We confirm that a PCR length assay can be used for separation of P. saxatilis s. str. from P. ernstiae and P. serrana because across our sample, P. saxatilis s. str. consistently includes a group I intron c. 200 bp. Using sequences for specimen identification, we test previously proposed characters to diagnose specimens and use multivariate analysis to identify the most consistent features which may be used for identification among species. First, we test lobe morphology, presence and amount of pruina, distribution of isidia, lobe tip colour, and chemistry. Second, we use classification trees that quantify the contributions of 1) morphological and chemical factors, and 2) morphological and ecological factors, to a priori ITS-barcoded specimens. Parmelia saxatilis s. str., P. ernstiae and P. serrana all occur across the sampled gradient but differ in the frequency of occurrence, with P. saxatilis s. str. more frequent in the relatively drier east, and P. ernstiae more frequent in the wetter west. Parmelia serrana was collected around a third as often as the other two species, but more frequently on tree branches than expected. For all the morphological characters examined, all the species show some overlap and no morphological features are diagnostic, though trends are apparent by species. The classification tree approach holds promise for discovering the most meaningful variation for field workers to approach correct identifications. Chemical variation using TLC is perhaps the best way to distinguish most specimens but, even here, overlap in chemosyndromes exists among the species.