Hypothetically, the alpine and high elevation moss flora reached central Mexico by migration from northern latitudes following the western mountain ranges. Study of 774 specimens belonging to eighteen species of Grimmia identified four patterns of distribution in Mexico: species restricted to the Neovolcanic Belt, those mainly distributed in the northwestern states, widely distributed taxa, and endemic species. Track analysis showed that the generic distribution indeed followed the western mountains. Modeling was introduced to determine the potential ranges for most Mexican species of Grimmia and review the migration hypothesis. The resulting potential distribution maps using maximum entropy show that several species have discontinuous ranges in the northwestern states. Other taxa are restricted to the Neovolcanic Belt, and still others extend their potential distribution to stations in southern Mexico and Guatemala. Although the original hypothesis proposed that the high altitude moss flora was derived from temperate North America may still be acceptable, the South American distribution of various species indicate that migration may have also proceeded from the south.

Climacium is a small but morphologically distinctive genus (“tree mosses”) with four species distributed primarily in the Northern Hemisphere. Climacium dendroides occurs around the globe at northern latitudes with disjunct populations in Mexico and New Zealand, whereas C. americanum and C. kindbergii are endemic to eastern North America and C. japonicum is limited to eastern Asia. Using nucleotide sequence data from five plastid loci plus the nuclear ribosomal ITS region we assessed evidence for monophyly of taxonomic species and tested the hypothesis that C. americanum and C. kindbergii from eastern North America have a sister group relationship with C. japonicum from eastern Asia. Climacium japonicum is resolved as sister to a clade containing the circumboreal C. dendroides, C. americanum, and C. kindbergii. Climacium americanum and C. kindbergii were not resolved as monophyletic based on sequence data but together they composed the sister lineage to C. dendroides. Geographically disjunct populations of C. dendroides in Asia, Mexico, the United States, and Canada vary at only a few polymorphic nucleotide sites across the three loci. The disjunctive New Zealand plants of C. dendroides are related to Asian accessions.

In North America, the widespread sorediate lichen known as Hyperphyscia adglutinata is shown to be heterogeneous. It contains two distinct species, one with primarily laminal soralia and another with marginal soralia. The latter taxon is here described as the new species H. confusa. Hyperphyscia adglutinata and H. confusa have broadly overlapping distributions in North America, especially in the Midwest and Great Plains states. Where they are sympatric, H. confusa is generally the more common of the two. Descriptions and discussions for H. adglutinata and the two other sorediate North American species, H. minor and H. pyrithrocardia, are also included, along with a key for separation of the four species. Hyperphyscia pyrithrocardia is reported for the first time from North America.

The genetic relationships and species boundaries of three species of Aerobryopsis, including a new one and a closely related taxon, Aerobrydium filamentosum within the Meteoriaceae of the Western Ghats of India were estimated based random amplified polymorphic DNA (RAPD) markers and morphological characters. Using 12 decamer primers 72 RAPD markers were identified, of which 69 (96%) were polymorphic. Amplicons of the primers OPF-01 and OPD-08 served as distinct markers to discriminate the species of Aerobryopsis and Aerobryidium filamentosum. The multivariate analyses of morphological and molecular data indicate that all the samples belong to four distinct species. RAPD proved to be a useful tool to detect genetic relationships of these closely related taxa and Aerobryopsis eravikulamensis Manju & Rajesh, a new taxon, is illustrated and described.

The occurrence of Platismatia erosa in Tibet and adjacent regions is reported. The shape of (hitherto rarely found) apothecia and pycnospores (the latter observed for the first time) are illustrated and compared with those of European material of P. glauca. TLC analyses of P. erosa samples revealed two substances, hitherto unknown in Platismatia, namely pannaric acid and jackinic acid, the latter also found in fruiting material of Platismatia glauca from Europe. Two chemotypes of P. erosa are recognized: chemotype I with caperatic acid as main fatty acid, and chemotype II (found only once) with jackinic acid as main aliphatic substance.

Based on field trips between 1995–2007, rare and noteworthy lichens from the Altai Mountains in southern Siberia are described. Bacidia zerovii Oxner is recognized as a synonym of Scoliciosporum chlorococcum (Graewe ex Stenh.) Vězda. Lecidea brenneri H. Magn. is lectotypified and synonymized with Lecania cyrtellina (Nyl.) Sandst. The new combination Puttea exsequens (Nyl.) Printzen & Davydov is introduced for Lecidea exsequens Nyl. and is the oldest validly published name for Lecidea gibberosa sensu Th. Fr. non Ach. Of the 33 species reported here, five species – Lecania croatica, Lecanora pseudosarcopidoides, Lecidea, L. sanguineoatra, Puttea exsequens and Rimularia fuscosora are new for Asia and Russia, Buellia arborea is new to Asia, Lecanora farinaria is new to Russia, Caloplaca herbidella, C. sorocarpa, Fellhanera subtilis, Lecidea pullata, and Pertusaria coccodes are new to Siberia. Several species are reported as new to West or South Siberia. Most corticolous lichen species display a more or less circumboreal distribution and also occur in Europe and North America.

Six new species of Graphidaceae are described from Sri Lanka, four in Graphis sensu Staiger and one each in Fissurina and Thelotrema. Fissurina srilankensis Weerakoon, Wijeyaratne & Lücking is characterized by lirellae with well-developed labia and comparatively large, muriform ascospores. Graphis allugallenensis Weerakoon, Wijeyaratne & Lücking is similar to G. vittata but has a distinctly verrucose thalline margin along the lirellae. Graphis dotalugalensis Weerakoon, Wijeyaratne & Rivas Plata resembles G. proserpens in the exposed lirellae with striate labia and apically carbonized excipulum but differs in the comparatively large ascospores. Graphis knucklensis Weerakoon, Wijeyaratne & Wolseley features lirellae with striate labia, an inspersed hymenium, and norstictic acid as secondary compound. Graphis srilankensis Weerakoon, Wijeyaratne & Lumbsch has entire labia with a completely carbonized excipulum, inspersed hymenium, transversely septate ascospores, and produces norstictic acid. Finally, Thelotrema pseudosimilans Weerakoon, Wijeyaratne & Lumbsch is close to T. similans in the corticate thallus and prominent apothecia with narrow pore, but has consistently larger ascospores.

The Hypogymnia austerodes group is an assemblage of mostly boreal and arctic-alpine lichens traditionally comprising three wide-ranging sorediate and/or isidiate species, H. austerodes, H. bitteri and H. subobscura. Here we describe four additional members of this group – H. dichroma sp. nov., H. protea sp. nov., H. salsa sp. nov. and H. verruculosa sp. nov. – which have until now been treated within H. austerodes s. lat. Our new species are primarily epiphytic, and are currently known only from Cordilleran western North America. They differ from other members of the H. austerodes group both morphologically and in their virtually consistent production of apinnatic acid. Hypogymnia protea is by far the most variable of the new species, uniting two putative taxa here designated as morphs “disjuncta” and “tessellata”. Reliable discrimination of the segregate species requires careful attention to their vegetative reproductive structures, which are described in detail. A key to all treated species and their recognized morphs is provided. Earlier reports of H. farinacea from western North America appear to be based on schizidiate material of H. protea morph “tessellata”. Whether H. farinacea actually occurs in North America remains an open question.

Bryoria divergescens, which was previously known only from the 19^th century holotype collection, has been rediscovered in various localities in Yunnan and also in Sichuan, southern China. This species should now be considered an endemic to the Hengduan Mountains region. It is characterized by its erect thallus, 3–8 cm tall, main branches 1–2 mm in diam., true lateral spinules, sparse pseudocyphellae, ±ciliate apothecia, the presence of fumarprotocetraric and lobaric acids. It usually grows on branches of conifers.

The circumscription of the Fabroniaceae is revisited based on phylogenetic inferences from published rps4 (cpDNA) and nad5 (mtDNA) sequences. Only Ischyrodon forms a clade with Fabronia, a relationship defined by the wavy-walled exothecial cells as a possible synapomorphy. The genus Levierella is nested within the Entodontaceae, Dimerodontium among taxa traditionally associated with Leskeaceae and the position of Rhizofabronia is uncertain.

We present an analysis of edaphic and phytosociological factors controlling the distribution of 36 moss species found in a northern hardwood forest. The soil chemistry, soil physical measurements, tree importance values and plot understory percent cover were analyzed for 153 plots (m³) located along a 1.8 km transect in Glenmeal State Forest, Pierrepont NY. Relationships between edaphic and phytosociological factors and species presence and absence were evaluated with non-metric multidimensional scaling, cluster analysis and Kruskall-Wallis tests. Soil depth, calcium, manganese, pH, CEC, light intensity, occurrence of Acer saccharum Marshall, Fraxinus americana L., Tsuga canadensis (L.) Carriere, and Quercus rubra L. percent living cover, percent graminoid, and percent tree cover were observed to exert the strongest influence on species presence and absence and species assemblages. Based on their responses to environmental variables the 36 moss species can be segregated into four groups defined primarily by soil calcium, potassium, CEC, moisture, and organic matter.

A taxonomic treatment based on field studies, examination of herbarium collections, and previously published molecular data is provided for the North American species of the Sphagnum subsecundum complex. Sphagnum platyphyllum, S. contortum, S. lescurii, and S. subsecundum are gametophytically haploid. Sphagnum missouricum and S. carolinianum are gametophytically allodiploid. A single allodiploid population of S. platyphyllum and a homoploid (haploid) hybrid between S. contortum and S. subscundum, previously documented genetically, are described and illustrated (but neither distinguished taxonomically). Epitypes are designated from (haploid) S. lescurii and (allodiploid) S. missouricum because the ploidal level of the original type material cannot be determined unambiguously. In North America, S. subsecundum is restricted to the eastern part of the continent, as western plants named this species are not conspecific. North American plants named S. inundatum are considered synonymous with either S. lescurii (when haploid) or S. missouricum (when diploid).

Morphology and ITS relationships are compared for 111 Sciuro-hypnum specimens, 95 of which belong to S. curtum, S. hylotapetum, or the S. reflexum complex. In the latter, S. reflexum is probably ancestral. Within the S. reflexum complex ITS haplotype relationships are congruent with morphology for S. brotheri, S. dovrense, S. glaciale, and S. ornellanum, and support the recognition of the two new species S. sinolatifolium and S. sichuanicum, whereas incongruence occurs for several species. In an ITS haplotype context, S. tromsoeense and S. latifolium are resolved as polyphyletic, and S. altaicum, some specimens of S. oedipodium, and S. curtum–S. starkei intermediates cannot be distinguished from S. reflexum. Sciuro-hypnum fuegianum is molecularly identical and morphologically similar to S. glaciale, and is considered conspecific with the latter. There is no evidence to suggest that ITS a priori is more reliable than morphology, and we therefore suggest that the abundant incongruent patterns reflect either 1) a young age in terms of number of generations in relation to the rate of ITS differentiation and associated incomplete lineage sorting and occasional hybridization events, 2) a faster rate of morphological than ITS evolution, 3) the existence of many lineages that are propagated by selfing, or 4) regional differences in extinction rates during the Pleistocene glaciations. However, additional information is required to decide which of these is/are most important. Finally, S. squarrosum, a morphologically distinct species that molecularly belongs outside the S. reflexum complex, is described as new.

Gyalidea fuscoclavata is described from one locality in the forest-steppe ecotone in south-western Argentina, where it grows on bark of the shrub Berberis microphylla. The new species is characterized by small (0.1–0.25 mm) black apothecia, 3-septate ascospores, apically thickened paraphyses with brown pigmented caps and KI blue hymenium.

Sphagnum perichaetiale Hampe and S. recurvum P. Beauv. are reported as new to Argentina based on collections from the Corrientes province. The presence of S. recurvum in this province is the southernmost locality in America. Sphagnum magellanicum Brid. and S. cuspidatum Ehrh. ex Hoffm. should be excluded from the bryological flora of the province of Corrientes. Descriptions, illustrations, SEM photographs, habitat, ecology and distribution are given.