The sterile asexually reproducing lichen Lecanora anakeestiicola is described as new to science from the southern Appalachian Mountains. This species is known from two populations that occur on shaded outcrops of the Anakeesta Formation at high elevations. It can be recognized by its dimorphic thallus with flaccid, ecorticate pseudopodetia and by the production of usnic acid in addition to zeorin. It is similar to Lecanora phryganitis, a narrow endemic of the Pacific Coast, which differs in the production of xanthones and in having tangled pseudopodetia that are stiff and hard due to the presence of a well developed cortex. It is also superficially similar to Leprocaulon americanum and L. quisquiliare, which are allopatric species that differ in having erect pseudopodetia with a stiff central cord.

Leptogium specimens from all over the world with smooth to rugulose upper surface and flat, rotund and elongated lobules or denticules on the thallus or apothecia have been commonly identified as Leptogium denticulatum. However, Leptogium denticulatum has denticules only on the margin of the apothecia and is not a pantropical species. Leptogium brasiliense is considered a synonym of L. denticulatum. Leptogium mastocheilum, until now considered a variety of L. moluccanum, is recognized as a separate species. Specimens identified as L. denticulatum from Brazil, New Zealand and the U.S.A. are herein described as the new species L. atlanticum, L. oceanianum and L. joergensenii.

Physcomitrella, as traditionally defined, accommodates certain Funariaceae with immersed and cleistocarpous capsules. Recent molecular inferences revealed that the three or four taxa typically recognized within Physcomitrella did not arise from a unique common ancestor, and hence that their morphological similarities likely resulted from convergence, while one potential taxon, P. patens subsp. californica ( = Physcomitridium readeri s.l.), is currently regarded as a polyphyletic entity, making Physcomitridium polyphyletic. Following recent discoveries that would greatly expand the known range of two taxa, we sampled populations of Physcomitrella s.l. from all main geographic regions, and sequenced the nuclear ITS regions and four plastid loci to assess the geographic circumscription of each clade. We recovered three unambiguous monophyletic entities matching the three morphotypes recognized by Fife, each with a distinct geographic range: Physcomitrella patens s.str. with a range in Europe and North America extended to East Asia (China); P. magdalenae with a range from West and Central Africa extended eastwards to Ethiopia; and Physcomitridium (Physcomitrella) readeri from western Europe and western North America to Japan and Australia, plus a doubtful occurrence in China. Although the distinction of P. californica from P. readeri remains doubtful, we reject the hypothesis that Physcomitridium is polyphyletic, arguing that this resulted from a misidentification of the sequenced voucher.

Mat-forming “ground layers” of mosses and lichens often have functional impacts disproportionate to their biomass, and are responsible for sequestering one-third of the world's terrestrial carbon as they regulate water tables, cool soils and inhibit microbial decomposition. Without reliable assessment tools, the potential effects of climate and land use changes on these functions remain unclear; therefore, we implemented a novel “Ground Layer Indicator” method as part of the U.S.D.A. Forest Inventory and Analysis (FIA) program. Non-destructive depth and cover measurements were used to estimate biomass, carbon and nitrogen content for nine moss and lichen functional groups among eight contrasted habitat types in Pacific Northwest and subarctic U.S.A. (N  =  81 sites). Ground layer cover, volume, standing biomass, carbon content and functional group richness were greater in boreal forest and tundra habitats of Alaska compared to Oregon forest and steppe. Biomass of up to 22769 ± 2707 kg ha⁻¹ (mean ± SE) in upland Picea mariana forests was nearly double other reports, likely because our method included viable, non-photosynthetic tissues. Functional group richness, which did not directly correspond with biomass, was greatest in lowland Picea mariana forests (7.1 ± 0.4 functional groups per site). Bootstrap resampling revealed that thirty-two microplots per site were adequate for meeting data quality objectives. Here we present a non-destructive, repeatable and efficient method (sampling time: ca. 60 min per site) for gauging ground layer functions and evaluating responses to ecosystem changes. High biomass and functional distinctiveness in Alaskan ground layers highlight the need for increased attention to currently under-sampled boreal and arctic regions, which are projected to be among the most active responders to climate change.

In an investigation of Peltigera species in montane forests of northern China, a new species, P. isidiophora was identified based on morphological characteristics and DNA sequence data. It differs morphologically from other members of the P. canina-group by its laminal clustered isidia occurring in pits, shiny upper surface, and its slender, scattered and simple rhizines. It also differs chemically from morphologically similar species by two unnamed terpenoid metabolites detected by thin layer chromatography in solvent systems C and G. Comparisons of the ITS sequences, both in phylogenetic analysis and secondary structure models of ITS2, support the taxonomic distinctiveness of this species. A synoptic table to morphologically similar species, and a key to the species in the Peltigera canina group from China are provided.

Chaenotheca balsamconensis is described as new to science based on collections from the Great Lakes and Appalachians of eastern North America (Maine, New Brunswick, North Carolina, Ontario, Prince Edward Island and Québec), and one population from western North America (British Columbia). It is distinguished from other species of Chaenotheca by its restriction to Trichaptum abietinum as a substrate, almost exclusively immersed thallus, smooth ascospores, and the presence of a KOH red pigment in the stalk. Large-scale conifer fatalities in eastern North America have increased the available habitat for T. abietinum, which has likely caused a boom in the population of C. balsamconensis.

Lichens are known to be indicators for air quality; they also respond to climate. We developed indices for lichen response to climate and air quality in forests across the northeastern United States of America (U.S.A.), using 218–250 plot surveys with 145–161 macrolichen taxa from the Forest Inventory and Analysis (FIA) Program of the U.S. Department of Agriculture, Forest Service. Lichen indicator species for response to climate and air quality were selected using Indicator Species Analysis, correlations with environmental variables, and published literature. Ordinations were used to evaluate the strength and relationships of the final indices. The Pollution Index was calculated for a plot from abundances of 12 tolerant and 45 sensitive indicator species standardized by abundance of all lichen species. The Index was correlated with modeled deposition of acidifying sulfur and oxidized nitrogen and with lichen community ordination pollution axes. Analyses suggested separate response of lichens to fertilizing N (weak statistical support). The Climate Index, from abundances of 19 warmer and 47 cooler climate indicator species, was correlated with modeled minimum January and annual maximum temperatures, and with ordination climate axes. The two indices are statistically independent. Repeat sample variability for each index was 7–14.5% (lower with higher quality data), supporting detection of consistent trends of 16–20% change over time or variation across space. Variability of the Climate Index was more affected by data quality than that of the Pollution Index. The continuous gradient of Pollution Index values suggests the cleanest areas may have air pollution above a critical load to fully protect lichen communities. These Indices can be applied to track lichen responses using other data from our study regions; suitability should be tested before use outside of the study area.

Neobarya usneae Etayo is a relatively uncommon lichenicolous fungus that forms distinctive obpyriform ascomata on species of Usnea. The species is one of five known lichenicolous species in Neobarya, a genus established in the Clavicipitaceae that contains a variety of mycoparasitic species. The only molecular data for Neobarya species available in GenBank are for unidentified Neobarya species. We obtained sequences of ITS and nrLSU representing a culture and herbarium specimens of N. usneae from New Brunswick, Canada, and from a herbarium specimen of N. parasitica (Fuckel) Lowen, the type species of the genus, collected in Luxembourg, to determine the phylogenetic placement of these species. Our results indicate that N. usneae is not closely related to the type of Neobarya in the Clavicipitaceae, but is instead a member of the Hypocreaceae, the first lichenicolous species known for certain from this Hypocrealean family. Based on these results, we are now establishing a new genus, Lichenobarya, for N. usneae in the Hypocreaceae, and encouraging further study of other Neobarya species to establish their phylogenetic relationships, given the potential for genetic heterogeneity in the group.