Lichen-based indices were developed for monitoring local climate and air quality impacts in the United States of America (U.S.A.) Mid-Atlantic states (MidA). The U.S.A. Forest Service Forest Inventory and Analysis Program (FIA) uses such biological indicators to monitor forest environments. Index development used a unique combination of recommended analysis techniques. The Climate Index (Axis 1 of nonmetric multidimensional scaling [NMS] ordination of 189 plots, 80 lichen species) accounted for 44.7% of data variation, and was correlated with latitude, temperature and humidity (r² = 0.5 to 0.7). The Pollution Index was based on abundances of 10 tolerant and 27 sensitive lichen species selected from Indicator Species Analysis and other techniques (210 plots, 180 species). Strong quantitative support guided careful selection of pollution indicator species. The Pollution Index was strongly correlated with Al, Cu, Fe, N and S measured in lichen samples (51 plots; maximum r²=0.796), and with 51-plot NMS Axis 1 (r²=0.694; 41.7% of information) correlated with pollution. Indices were uncorrelated with each other or with nearby forest cover, another important factor. From within-site repeatability, Climate Index changes of 13–21% of full range and Pollution Index changes of 18–24% will be detectable. These indices fill a gap to complete FIA index coverage for much of eastern U.S.A. Both indices are suitable for application in other MidA studies. Comparisons with similar FIA studies supported guidelines for use of our indicator selection process and evaluation of environmental interactions to improve other studies.

A latitudinal diversity gradient (LDG), with increasing species richness towards tropical zones, has been amply documented in the literature for many organisms. Among the factors hypothesized to explain the LDG is Rapoport's rule, which postulates deceasing distribution ranges for species at lower latitudes, in turn fostering higher species richness per area. So far, little is known about LDGs and a Rapoport effect in lichens, and tropical regions or the Southern Hemisphere have not yet been considered in such studies. In order to elucidate a potential LDG in the Brazilian Atlantic Forest, species occurrence data from four representative families of largely epiphytic lichens were used: Graphidaceae, Lobariaceae, Parmeliaceae and Trypetheliaceae. We employed niche distribution modeling on a subset of species to surpass the limitation of geographically strongly unbalanced sampling in the study area, including sampling bias in the modeling approach. The four families presented significant LDGs which were, however, opposed in Lobariaceae and Parmeliaceae. Rare species that were not modeled further pronounced these patterns. Rapoport's rule, i.e. an inverse correlation between richness and mean species range, was supported for all four families. Richness values for the four families, and size ranges for Parmeliaceae, showed strong and significant correlations with bioclimatic parameters, particularly temperature and precipitation seasonality and precipitation in the driest quarter. We hypothesize that, based on the specific situation of the Atlantic Forest, the observed LGDs and Rapoport effects are secondary consequences of underlying environmental gradients that happen to run parallel to latitude, and that Rapoport's rule is not primarily linked to latitude but to gradients of adverse environmental conditions. Including rare species, predicted species richness values for the four studied families combined would result in between 400 and 700 species per 55 × 55 km grid cell.

Lecanora markjohnstonii is described as new to science from the southeastern United States, with a primary center of distribution in the southern Appalachian Mountain region. This sterile, sorediate crust is saxicolous on both sandstone and granite and occurs commonly in mixed hardwood-conifer forests with rock outcrops. It is characterized by a gray-green, rimose-areolate thallus, erumpent, raised soralia, and the production of atranorin together with 2-0-methylperlatolic acid. Molecular phylogenetic analyses of newly generated rDNA assemblies from a broad sampling of lineages within the Lecanoromycetes and Arthoniomycetes inferred placement of the unknown crust in the Lecanoraceae, specifically within Lecanora. Analysis of the mtSSU gene region then inferred placement in the Lecanora subfusca group. Finally, a fully assembled and annotated mitochondrial genome was compared to other lichenized fungal mitogenomes, including the publicly available Lecanora strobilina mitogenome, and showed that the gene region atp9 was missing as in other members of the Lecanorales.

Ramalina sarahae is described as new to science and considered to be closely related to the widespread R. lacera. It has a cortex without chondroid strands but differs from R. lacera in having a densely caespitose thallus of thin branches with only pseudocyphellae. The species is considered to be naturally rare, occurring in a small area of San Miguel Island in southern California, and on San Nicolas Island. Currently eight species of Ramalina are known from the Channel Islands.

Coscinodon horridus, formerly Grimmia horrida, is reported as new to France from two localities. Sporophytes are described for the first time. Morphological and molecular evidence are presented supporting the transfer of G. horrida to Coscinodon. The variability of the species and reproductive traits are discussed and it is compared with morphologically similar taxa.

The new fruticose lichen species Trapeliopsis studerae with fruticose growth form, branches mostly flat to partly curling up, but lower down often almost cylindrical, much irregularly branched, 0.1–0.2 mm thick and 0.3–0.6 mm wide, upper surface olive grey, pycnidia that probably belong to the lichen are present on some older parts of the thallus, superficial, brown, conical to somewhat inflated, conidia hyaline, clavate, 8–11 × 1.5–2.5 μm, and chemistry gyrophoric acid, is described from rock outcrops in a remnant of Atlantic Forest in Alagoas, Northeast Brazil, viz. Reserva Biólogica de Pedra Talhada, near the city of Quebrangulo, in the middle of the semiarid region in Northeast Brazil. It represents a new and independent lineage of fruticose lichens, the first found in the Trapeliales and only the second in the subclass Ostropomycetidae. The morphology of this species is enigmatic: it somewhat resembles a Siphula or a Stereocaulon, but it is irregularly branched without main stem, lacks cephalodia and apothecia, and it differs from all known species in these genera by the gyrophoric acid chemistry. It forms dense mats on siliceous rock that is influenced by run-off water. It typically grows at the upper ends of gullies that are occupied lower down (where there is more often water) by cyanophilic lichens such as Peltula clavata and Jenmania osorioi. The habitat is extremely poikilohydric; this lichen is occasionally totally submerged, but usually completely dry.

Bacidia gullahgeechee is described as new to science and easily recognized by the combination of a leprose thallus, minute tan to dark reddish-brown biatorine apothecia, and production of perlatolic acid. The species forms extensive, conspicuous colonies on palmetto (Sabal palmetto) trunks in maritime forests of the Ashepoo-Combahee-Edisto (ACE) Basin of South Carolina, one of largest protected estuaries in the eastern United States, where it is presumed to be narrowly endemic.

Dense High-montane Ombrophilous Forest possesses environmental characteristics that give it unique structure and floristic composition. Assuming that elevation and associated variables act as filters for bryophyte communities, the purpose of this study was to analyze the distribution of bryophytes in relation to vertical phorophyte zonation within the nebular forest, a type of rainforest in a high altitude environment, characterized by the occurrence of constant cloud, in Parque Estadual Pico do Marumbi, Paraná, Brazil. All bryophytes occurring on twenty-eight trees in the elevation range of 1000 to 1500 m were sampled and analyzed in six predefined vertical zones. Samples were identified using standard methods and references for bryophytes, and their coverage and abundance was characterized for each tree. Comparisons among zones were done using cluster analysis and diversity. A total of 96 species and 31 families were recorded, with Lejeuneaceae being the richest family followed by Frullaniaceae. Some species were common to all areas, and eight new occurrences for the state of Paraná are reported. This study found high diversity (ranging from H′ = 2.6 to H′ = 4.1) and abundance (0.01 to 0.07) of bryophytes, with a predominance of liverworts. Among the areas analyzed, the floristic compositions of only two differed by more than 50%. This study represents the first evaluation of bryophytes in this elevation range, and the results confirm the importance of conserving high montane regions.

Didymodon buckii J.A.Jiménez & M.J.Cano is described as a new species from central Peru and northwestern Argentina. It is readily distinguished from all congeners by having bistratose to tetrastratose leaf margins from the apex to near the base and long-cylindric, thickened and deciduous leaf apices that are strongly channeled ventrally. Additionally, the new moss is characterized by its linear-oblong leaves, papillose distal laminal cells, and costa with a hyaline area of rectangular cells on the distal ventral surface and with ventral stereids below midleaf. Drawings and light microscope photographs of the main characters are given, and possible confusion with other closely related taxa is discussed. Distribution of the new species is mapped.

Tortella mediterranea is described as a new species from the Mediterranean Basin of southern Europe. It is mainly characterized by (1) absence of a stem central strand, (2) lanceolate leaf shape, (3) rather gradual limb-sheath transition, (4) partial presence of elongate marginal cells in the upper half of leaf and (5) ventral costal stereid band usually stronger than the dorsal. Chloroplast rps4 and nuclear ITS sequences were invariable within the studied specimens of the species, suggesting a low genetic variability, and the phylogenetic position is rather isolated with only obscure affinities to the group of closely related taxa around T. tortuosa and to T. fasciculata. The new species, seemingly a rather rare plant, was collected from dry and sunny to shaded limestone rocks. In addition, new molecular data for T. nitida s.str. and putative var. irrigata are provided and taxonomic problems within this variable species are discussed.

In the past decade, floristic studies have rebounded as checklists are fundamental for executing meta-analyses which address ecological, biogeographic and evolutionary questions of broad geographic scope. Despite the importance of checklists as baseline records of local diversity and distributions, few attempts have been made to quantify sampling effort and species detectability within and among study sites. Quantitative floristics, which combines the use of checklists with statistical methods for estimating local richness, is a promising method for characterizing the completeness of checklists especially for cryptic components of biodiversity. For bryophytes, quantifying levels of detectability among substrate types is of central importance, especially in tropical forests where much of their diversity is harbored in difficult to access habitats such as the tree canopy. In light of the need to establish quantifiable protocols of detectability in poorly studied tropical regions, we present a bryophyte checklist for the Jaú National Park (JNP), located in the heart of the Amazon, and estimate local species richness and detectability as it relates to five substrate types (epiphytes, epiphylls, epixylic, epipetric and soil). Identifications from 712 collections made during four excursions over the past decade to JNP revealed 150 species consisting of two new country records and five new state records, along with 20 rarely collected Amazonian endemics. Despite our intensive sampling, which included systematic canopy collections during one of the excursions, Chao richness index estimated that ca. 46 species (nearly one-third of those presently observed) remain undetected from JNP. Furthermore, levels of detectability among substrates varied widely, where observed epiphyte richness, in contrast to the other substrates types, most closely approximated the estimates. Our results illustrate the need for quantitative richness estimates as a means to increase the accuracy of checklist data, particularly when used in meta-analyses addressing global-scale questions.