Melanotopelia africana is described as new to science from Rwanda (continental Africa) and La Réunion (Mascarenes archipelago). Topeliopsis muscigena is here reported for the first time from La Réunion.

Conservation assessments of lichens have usually been based on scattered and methodologically diverse data. We illustrate the contribution of standardized inventories to conventional data sources by assessing the status of two conspicuous epixylic Cladonia species of conservation concern in Estonia. A time-limited inventory of all lichen species was carried out in 92 stands (2 ha each) in a balanced design of forests and clear-cuts. Cladonia parasitica (previously considered Regionally Extinct) was present in 13 stands with a total of 33 individual records, almost exclusively in dry boreal old-growth forests and clear-cuts. Thirty-six records of C. norvegica (previously six records) were made in 17 stands, most frequently in mature meso-eutrophic forests. On average, 1·5 hours of inventory were needed to discover C. parasitica in a stand, and 2 hours for C. norvegica. The scarcity of old records was probably due to the low local abundance of the species, their habitats being unpopular among lichenologists and expenditure of too short an inventory time in the field. Using habitat and frequency data, we estimate that the national population sizes of the species clearly exceed those set as IUCN criteria for species at risk. The key issue is the expected trend in substratum abundance, which suggests C. parasitica to be Near Threatened. We recommend stratified random sampling as an efficient method to collect quantitative information for lichen flora assessments.

Bacidia rosellizans S. Ekman is described as new to science. Morphologically, the new species is similar to the type species of the genus, B. rosella (Pers.) De Not., particularly in the pale pink and pigment-deficient apothecia and in having the proper exciple and upper part of the hymenium inspersed with minute crystals that consist at least partly of atranorin. Bacidia rosellizans, however, differs in having a thin whitish thallus, smaller apothecia and a thinner apothecial margin, a dense layer of crystals along the excipular rim, shorter and narrower ascospores with fewer septa, and septate conidia. Whereas B. rosella is a species occurring in the nemoral zone of Europe and possibly northernmost Africa and parts of Asia (but not North America), B. rosellizans is found mainly on Populus and Salix in taiga. This species is currently known from Sweden, Russia, Canada and the USA. It was erroneously treated as Bacidia rosella in a monograph of North American corticolous species of Bacidia and Bacidina by Ekman (in Opera Botanica 127, 1996).

Fourteen genera belong to a monophyletic core of cetrarioid lichens, Ahtiana, Allocetraria, Arctocetraria, Cetraria, Cetrariella, Cetreliopsis, Flavocetraria, Kaernefeltia, Masonhalea, Nephromopsis, Tuckermanella, Tuckermannopsis, Usnocetraria and Vulpicida. A total of 71 samples representing 65 species (of 90 worldwide) and all type species of the genera are included in phylogentic analyses based on a complete ITS matrix and incomplete sets of group I intron, β-tubulin, GAPDH and mtSSU sequences. Eleven of the species included in the study are analysed phylogenetically for the first time, and of the 178 sequences, 67 are newly constructed. Two phylogenetic trees, one based solely on the complete ITS-matrix and a second based on total information, are similar, but not entirely identical. About half of the species are gathered in a strongly supported clade composed of the genera Allocetraria, Cetraria s. str., Cetrariella and Vulpicida. Arctocetraria, Cetreliopsis, Kaernefeltia and Tuckermanella are monophyletic genera, whereas Cetraria, Flavocetraria and Tuckermannopsis are polyphyletic. The taxonomy in current use is compared with the phylogenetic results, and future, probable or potential adjustments to the phylogeny are discussed. The single non-DNA character with a strong correlation to phylogeny based on DNA-sequences is conidial shape. The secondary chemistry of the poorly known species Cetraria annae is analyzed for the first time; the cortex contains usnic acid and atranorin, whereas isonephrosterinic, nephrosterinic, lichesterinic, protolichesterinic and squamatic acids occur in the medulla. Notes on the anatomy of Cetraria annae and Flavocetraria minuscula are also provided.

Twenty-three species of epiphytic Caloplaca are recognized in India, of which Caloplaca himalayana Joshi, Y. & Upreti, characterized by thin, continuous, yellowish thallus, numerous ferruginous-red to brownish red, flat to subconvex apothecia with a persistent proper margin and lignicolous habitat, is described here as a new species. Because of the ferruginous coloured apothecial disc, the new species is provisionally placed in the ferruginea group until a taxonomic treatment of the whole group has been carried out. The ferruginea group is characterized by a whitish to grey (rarely yellowish) crustose thallus, a ferruginous to rarely blackish apothecial disc, biatorine to lecanorine exciple, thick-walled spore septa and the chemosyndrome C. The taxonomic affinities of the new taxa with several other taxa, including species of ferruginea group, are discussed. Two new records for India are also recorded: Caloplaca alnetorum Giralt, Nimis & Poelt and C. crocea (Kremp.) Hafellner & Poelt. A key to all the corticolous Caloplaca species occurring in the Indian subcontinent is also provided.

The lichen genus Stirtonia has been revised. Thirteen species are accepted in the genus, including three new to science, viz. S. curvata from Irian Jaya and Java, S. schummii from the Seychelles and S. neotropica from Costa Rica and the Dutch Antilles. The known range of the genus is extended from Asian to pantropical. The genus is most diverse in the palaeotropics.

The genus Mycoblastus in cool temperate latitudes of the Southern Hemisphere is reviewed. Eight species are treated in detail: M. bryophilus Imshaug ex Kantvilas sp. nov., from Campbell Island and Tasmania; M. campbellianus (Nyl.) Zahlbr., M. coniophorus (Elix & A.W. Archer) Kantvilas & Elix comb. nov. and M. dissimulans (Nyl.) Zahlbr., all widespread across the austral region; M. disporus (C. Knight) Kantvilas comb. nov., from New Zealand and Tasmania; M. kalioruber Kantvilas sp. nov, from Tasmania; M. sanguinarioides Kantvilas sp. nov., from Tasmania and south-eastern Australia; and M. leprarioides Kantvilas & Elix sp. nov., from south-eastern Australia (Victoria). Notes are provided on many other species of Mycoblastus, including those recognised for the Northern Hemisphere, and those originally described from austral regions but now excluded from the genus. Major characters of the genus are discussed, including thallus morphology and chemistry, apothecial pigments and ascus structure. It is suggested that the genus is heterogeneous and that some of its closest affinities may lie with the family Megalariaceae and the genus Japewia.

Algal genotypes should freely associate with different lichen fungi that grow in the same confined habitat giving the appearance of low levels of selectivity and specificity. If genetic compatibility between algal and fungal partners limits the combination of partners, then some degree of taxonomic specificity should be evident. This study examined the photobiont composition in a community of epiphytic lichens on Jack Pine to investigate selectivity and specificity. The objectives of the study were to infer algal identity, to infer photobiont dispersal, and to investigate the distribution of algal genotypes relative to the fungal partner. Photobiont variability was determined by Restriction Fragment Length Polymorphism (RFLP) and nucleotide sequences of the Internal Transcribed Spacer (ITS) of ribosomal DNA (rDNA). Seven species of lichen-forming fungi are reported to associate with five divergent algal genotypes, with only one species, Evernia mesomorpha, showing some degree of selectivity and specificity. The algae represent at least two species (Trebouxia jamesii and T. impressa) for the area confined to 200cm2 on the north side of 20 Jack Pine trees. Gene flow was inferred in this tightly defined community of lichenized algae. The algal sharing and inferred gene flow may suggest that soredia provide a means of algal transport and distribution among lichen-forming fungi in the habitat.

A monograph of the genus Placomaronea is presented; all species described earlier are revised, a total of six species is recognized, and an identification key is presented. In addition to the three previously known species, P. candelarioides, P. lambii and P. mendozae, three new species are described: Placomaronea kaernefeltii is a large rosette-like species known from one locality in northernmost Chile; Placomaronea fuegiana is a bullate, areolate species described from Tierra del Fuego, Argentina; Placomaronea minima is a small, areolate to minutely lobate species described from Chile and Argentina, and is the first species of Placomaronea to be reported from the African continent. In a phylogenetic analysis of nuclear ITS rDNA, Placomaronea is shown to form a monophyletic group within the Candelariales.

Parmeliella zeylanica is described as a new species in the P. mariana group, although it differs from all known species in the group by not having radiating marginal lobes resting on a distinct mat of rhizohyphae. It is as yet known only from the highlands of Sri Lanka. The new combination Parmeliella leiostroma (Nyl.) P. M. Jørg. is made for a closely related species from the same region, and it is shown that Parmeliella endomilta var. achromatica Makhija & Adawara falls within the variation of Parmeliella mariana (Fr.) P. M.Jørg. & D. J. Galloway, and is not closely related to P. endomilta.

A new species, Placocarpus americanus, is described from the Santa Monica Mountains in Southern California. It is a juvenile parasite on Protoparmeliopsis muralis and differs from Placocarpus schaereri in having smaller non-halonate ascospores, a negative iodine reaction of the medulla, lack of inspersion of the medulla with small crystals, and having a thallus of dispersed areoles.

Rinodina brasiliensis, a corticolous isidiate species with large Pachysporaria-type ascospores is described from south-eastern Brazil. The new species is closely related to R. dolichospora and to R. guianensis.Rinodina confinis is a synonym of R. dolichospora. Notes on the taxonomy, morphology, anatomy, chemistry and distribution of these three taxa are given. Descriptions and iconography are provided. A key to species is also included.

The species richness and composition of lichens was quantified for four temperate broad-leaved tree species (Acer platanoides, Fraxinus excelsior, Tilia cordata and Ulmus glabra) in boreo-nemoral forests on the talus slope of the North-Estonian limestone escarpment (North-Estonian Klint). Thirteen study sites were distributed along the klint on a west to east gradient. The effects of tree and stand characteristics and geographical location of a stand on composition and diversity of epiphytic lichens were evaluated by multivariate analyses (DCA, CCA, pCCA) and by general linear mixed models (GLMM). Tree level variables (e.g. bark pH, bryophytes cover and host tree species) explained the largest fraction of the variation in lichen species composition. However, species richness and composition were significantly influenced also by the unique habitat conditions of klint forest (length of the forest fragment, proximity of the stand to the sea and height of the escarpment). A significant correlation between stand locality and lichen diversity on the tree bole was found which is most likely related to local air pollution gradients caused by alkaline cement dust and acid pollutants in the north-eastern part of Estonia.

The fine-scale genetic variation and population structure of lichen-forming fungi is little known and sampling strategies are rarely recommended or discussed. I tested if the sample sizes of molecular data sets used in recent population studies of Xanthoria parietina revealed all haplotypes potentially present and, accordingly, quantified how many haplotypes were potentially missing in the samples. Data sets were concatenated from two geographical regions in Scandinavia and investigated if the sampling reached saturation at two levels: 1) individual-based using rarefaction curves and 2) population-based using species accumulation curves. At both levels, the matrices of two molecular markers (IGS and ITS) were analysed separately. The molecular markers show similar and parallel patterns in all analyses. Rarefaction analyses did not reveal different patterns for populations in different habitats, i.e., bark and rock. Species accumulation curves estimated with the Chao 1 richness estimator indicated that 23% of the IGS and 8% of the ITS haplotypes were not detected. Corresponding figures from an abundance-based coverage estimator (ACE) were 37% and 18%. Pilot studies are recommended to determine appropriate sample sizes for genetic-based population studies of lichen-forming fungi.

Umbilicaria iberica and U. maculata are described as new to science on the basis of morphological and molecular data. Umbilicaria iberica is similar to U. polyphylla but differs in having a monophyllous thallus with a distinctive white reticular pattern over the umbilicus and actinodisc apothecia. Umbilicaria maculata is similar to U. cylindrica but this new species is distinguished by its grey-brown thallus with sparse marginal cilia and white stains on the upper surface especially in the marginal zone, as well as by sessile apothecia with one or a few sterile fissures. Nuclear ITS and LSU rDNA have been used as molecular markers. In the phylogenetic analysis U. polyphylla falls into two well supported clades (A and B), one of which corresponds to the morphotype that is described here as a new taxon. Specimens previously recognized as U.cylindrica fall into three well supported clades: clade C corresponds to the typical morphotype, clade D corresponds to morphotype II described here as a new taxon, and clade E is morphotype III which is recognized as U. cf. umbilicarioides. Typical group I introns have been found in position 1506 of the nuclear SSU rDNA of Umbilicaria; a consensus secondary structure of these introns is presented and we conclude that they represent an important and valuable molecular marker which gives additional support to the ITS and LSU sequence phylogeny obtained.

Two surveys of the lichen and bryophyte flora growing on oak twigs from a Welsh and a Danish locality were compared with additional data on bark pH and % nitrogen in thalli of Hypogymnia physodes. Despite differences in climate and lichen flora, both sites showed a shift in the lichen communities from nitrogen sensitive (nitrophobe) to nitrogen tolerant (nitrophile) species, which was correlated with both increasing bark pH and an increase in total nitrogen in thalli of H. physodes. The floristic survey from Wales was a repetition of a study eight years earlier (Wolseley & Pryor 1999) now showing a loss of nitrophobes in all sites and the appearance of nitrophiles in pasture sites in 2003. This study demonstrates that lichens on twigs can be used as an early warning system to detect a response to changes in land management and nitrogen deposition.

Meridianelia maccarthyana Kantvilas & Lumbsch, gen. et sp. nov., is described, based on collections from Tasmania. This taxon represents only the second member of the family Elixiaceae. It is compared to Elixia flexella (Ach.) Lumbsch and to the superficially similar genus Trapelia. The family Elixiaceae is redefined briefly to account for the inclusion of a second genus.

This study aims to investigate patterns of species richness and abundance in relation to stand age in 71 Picea abies plantations, aged between 9 and 85 years, situated in the oceanic region of Central Norway. The study has shown that plantations within the oceanic spruce forests can support a relatively high number of epiphytic lichen species. Some of the oldest plantations hosted several old-forest associated species, e.g. Hypogymnia vittata, Lobaria pulmonaria, Pseudocyphellaria crocata and Ramalina thrausta. The number of species was influenced significantly by stand age and increased rapidly in stands <20 years old. Stands >30 years old showed no clear increase in species number, except for a high number of species in the two oldest stands. The colonization pattern could be characterized as an additional entrance of species, rather than by a replacement sequence. The probability of occurrence increased steeply at young stand ages (<20 years) for Bryoria spp., Cavernularia hultenii, Platismatia glauca, Parmelia sulcata and Usnea spp. A lower rate of colonization was characteristic for Alectoria sarmentosa, Parmelia saxatilis and Platismatia norvegica. The cover of foliose lichens on the branches showed an almost unimodal response to stand age. The cover of lichens was highest on branches in middle-aged plantations. The reason for the lower lichen cover in late successional stages, compared to middle-aged stands, could be due to reduced light in the lower canopy of mature plantations. Increased rotation cycle, creation of gaps and short distance to sources of propagules are factors suggested to promote species richness and abundance in forest plantations.