We studied lichen communities on bole and base tree trunk segments along forest edge-to-interior gradients on opposite sides of a major highway and a control site in central North Carolina, U.S.A., to investigate if these two communities differ and if so, do they differ in response to highway pollution. At each site we measured various environmental parameters including ambient air NO₂ concentrations, and sampled lichens on 5–7 trees along each of five parallel transects established at the forest edge and at 25, 60, 100 and 150 m into the forest. We compared lichen communities between the two trunk segments via species richness and composition by habit, photobiont type, and reproductive strategy. We then ran dual (bole and base) NMS ordinations with subsequent correlation/regression analyses to explore/test relationships of lichen parameters with environmental variables among the 15 sample transects combined. Species richness was similar between trunk segments at transect and site levels as well as overall. Bole and base communities were more compositionally similar to each other at the highway sites than they were at the control site, based on Bray-Curtis similarity indices (BC). Tree base communities differed in terms of functional groupings, with greater proportions of squamulose, cyanolichen and sterile species than found in tree bole communities, but varyingly so among sites. Patterns of bole-base BC values with distance from the forest edge were not apparent in any of the sites. Ordination analyses resulted in Axis 1 representing most of the variation for each trunk segment. Along this axis, correlations were similar between boles and bases, with the strongest ones involving lichen species richness (negative) and NO₂ concentrations (positive); notably weak correlations involved tree species number, canopy cover and DBH. Similar patterns were found when lichen species number was correlated with environmental parameters directly, with NO₂ concentration correlating strongest at each trunk segment. Among functional groups, % crustose and % fertile species on bases correlated significantly with NO₂. Lichen species–NO₂ relationships on boles and bases were both found to be highly significant quadratic relationships with base lichen richness being stronger.

The architecture and composition of the mitochondrial genome of bryophytes is currently considered much more stable and invariant than that of vascular plants. For example, liverworts and mosses appear to have nearly static mitochondrial genomes, whereas neither of two vascular plant mitogenomes sequenced to date share the same gene order. By contrast, the two available mitogenomes of hornworts, Nothoceros aenigmaticus and Phaeoceros laevis, show high consistency in gene content but differ in their gene order. To explore the patterns of hornwort mitogenome structure at a broader phylogenetic breadth and provide insights into plant mitogenome evolution, we assembled the complete mitochondrial genome from a third hornwort species, Anthoceros angustus Steph. Its mitogenome comprises 242,410 base pairs, and encodes 21 protein coding genes, three rRNA genes and 20 tRNA genes, with 38 introns disrupting 16 protein-coding genes, including three newly described introns, making it the most intron-rich plant mitochondrial genome determined to date. A total of ten putatively pseudogenized protein coding genes were found in Anthoceros; eight of them are shared with Nothoceros and Phaeoceros. The genic composition of the Anthoceros mitogenome differs from that of the other two hornworts by only one or two gene insertions or losses. The gene order in the Anthoceros mtDNA differs from that in Phaeoceros and Nothoceros by only one and three events of inversion or translocations, respectively. Overall, hornworts appear to have kept a stable mt genome structure, which could have characterized early land plant mt genome evolution.

Didymodon fortunatii Cardot & Thér. and Hymenostylium diversirete Broth. ex Hand.-Mazz. were previously known only from type collections and both placed into synonymy with Reimersia inconspicua (Griff.) P.-C.Chen when a new monospecific genus Reimersia P.-C.Chen was established. While the plants markedly resemble each other in general appearance and growth habit, a careful review of cellular architecture across the lamina has now identified several character states that differ significantly between them. The nomenclatural history of Reimersia has basically remained unchanged since its generic establishment in 1940. A new combination as Reimersia diversiretis (Broth. ex Hand.-Mazz.) Shevock, W.Z.Ma, S.He & D.G.Long is proposed and the genus Reimersia now contains two species endemic to Asia.

We provide a checklist and a key to the 26 species and one infraspecific taxon of the genus Gyalideopsis (Gomphillaceae) currently known from Brazil, including two species with unique hyphophores described as new to science herein: G. aptrootii Xavier-Leite, M.Cáceres & Lücking sp. nov., characterized by adnate, crescent-shaped hyphophores with moniliform diahyphae and broadly sessile, dark grey-brown apothecia with single, muriform, rather small ascospores; and G. marcellii Xavier-Leite, M.Cáceres & Lücking sp. nov., with mussel-shaped hyphophores similar to those of G. haliotidiformis but differing in the filiform diahyphae. The other taxa known from Brazil are: G. aequatoriana Kalb & Vězda, G. altamirensis Lücking & Umaña, G. applanata Herrera-Campos & Lücking, G. argentea (Mont.) Kalb & Vězda, G. brevipilosa (Kalb & Vězda) Lücking, Sérus. & Vězda, G. cochlearifera Lücking & Sérus., G. confluens Kalb & Vězda, G. ellipsoidea A.A.Menezes, M.Cáceres & Aptroot, G. epithallina Lücking, G. glauca (P.Karst.) Lücking, Sérus. & Vězda, G. haliotidiformis Kalb & Vězda, G. intermedia Lücking, G. kalbii Vězda, G. lambinonii Vězda, G. lecideina Kalb & Vězda, G. palmata Kalb & Vězda, G. robusta Kalb & Vězda, G. rostrata Kalb & Vězda, G. rubescens Vězda, G. rubrofusca Kalb & Vězda, G. vainioi Kalb & Vězda, G. verruculosa Vězda & Hafellner, G. vezdae Kalb, G. vulgaris (Müll.Arg.) Lücking f. vulgaris, and G. vulgaris f. albopruinosa Lücking.

A narrowly endemic species known only from the type locality in Shangsi Co., Guangxi, as well as a peculiar member of the Chinese Lejeuneaceae, Cheilolejeunea gaoi has previously been treated as a species of Cheilolejeunea. However, the presence of Allorgella-type denticulations formed by two adjacent cells on leaf and underleaf margins, small ovate leaf lobules without distinct teeth, ental hyaline papilla, and finely segmented oil bodies all suggest that it belongs somewhere else. Maximum likelihood, maximum parsimony, and Bayesian analyses of a three marker dataset (nrITS, cpDNA rbcL and trnL−F) derived from 85 accessions of Lejeuneeae and 15 outgroup species revealed that C. gaoi belongs to subtribe Echinolejeuneinae. Based on the results of phylogenetic analyses, combined with morphological data, we suggest here that C. gaoi should be established as a new genus, Gaolejeunea. We strongly recommend in situ or ex situ conservation activity for this species based on the IUCN Red List criteria.

A new species of Brachythecium Schimp., B. canobernabei J.D.Orgaz & J.Guerra is described for Japan based on morphological and molecular data. The species is distinguished morphologically by elongate, acuminate and decurrent ovate-triangular leaves with denticulate margins, subquadrate alar cells becoming rectangular and somewhat inflated in decurrencies, autoicous sexual condition and rough setae. Drawings and light microscope photographs of the new species are provided. A table with the diagnostic characters to distinguish this species from its closest species, and a phylogenetic analysis are also provided.

Among hitherto unidentified collections of lichens from Brazil and Venezuela, we have encountered several new taxa, twelve of which are described in the present paper, viz. Absconditella rosea, Absconditella viridithallina, Allographa hypostictica, Astrothelium miniannulare, Astrothelium rhinothallinum, Astrothelium trematum, Chiodecton graphidastroides, Graphis halonata, Lecanactis malmideoides, Maronora cyanosora, Rinodina densisidiata and Rinodina maronisidiata. The new genus Maronora is described to accommodate an enigmatic species with Lecanora habitus but with a Fuscidea ascus.

Nine species of lichens from Bahia are described as new: Arthonia saxistellata, Cladonia inflata, Cladonia lichexanthonica, Cladonia minisaxicola, Coniocarpon piccolioides, Pertusaria lichexanthofarinosa, Pertusaria lichexanthoimmersa, Pertusaria lichexanthoverrucosa and Physcia sorediiconvexa. Many of the new species contain lichexanthone in the cortex and the substance is reported for the first time from Cladonia.

The invalid combination Stirtonia alba (Müll. Arg.) ined., based on Arthonia alba Müll. Arg., is listed for the continental United States in several important online repositories, including CNALH, USDA PLANTS and EOL. Although Arthonia alba belongs in Stirtonia, the name cannot be used in that combination, as it is blocked by S. alba Groenh. ex Makhija & Patw., a species described from Java, Indonesia, and both taxa are distinct morphologically, anatomically and chemically. Here, we resolve this nomenclatural impasse by proposing the new name S. caribaea for A. alba. We examined further material identified as “A. alba / S. alba” from North America and the Caribbean. Specimens ascribed to “S. alba (Müll. Arg.) ined.” from North America (Louisiana, Florida) were found to be misidentifications in other genera, with only one collection confirmed as a Stirtonia. This specimen was determined to be S. punctiformis, and is here reported as new to North America, representing a northward range extension from Central America and northern South America. Therefore, the name “Arthonia alba Müll. Arg.” listed under Stirtonia in the North American lichen checklist should be removed. Caribbean material previously identified as A. alba was found to represent two species: A. alba s.str., here renamed S. caribaea, known from Cuba and St. John of the U.S. Virgin Islands; and S. borinquensis, which we describe as a new species from Puerto Rico.