The taxonomy of Cinclidium, with only four species recognized, has been remarkably stable compared to most other genera in the Mniaceae. Two bisexual diploids (C. stygium and C. subrotundum) with n = 14 and two unisexual haploids (C. arcticum and C. latifolium) with n = 7 have been accepted since 1877, when C. latifolium was the last of these to be described. In the course of our inquiries into the nature of polyploidy in the genus, we discovered a new, genetically distinct species that has previously been mistakenly referred to C. latifolium and which we originally assumed was C. subrotundum. Cinclidium alaskanum is also morphologically distinct from the other four species, occupies distinctive microhabitats on the North Slope of Alaska, and is unisexual and haploid with n = 7.

We studied the habitat preferences of various bryophytes on a landscape in which calcareous and granitic rocks interdigitate. On both substrates, plots were placed in sunny dry locations, shady dry locations, and along streams in wet locations. In other words, six habitat types were studied in a factorial design involving edaphics × moisture. Wet granitic habitat had the highest species richness, whereas wet calcareous habitat had the lowest species richness. In dry sites, shady plots had higher richness than sunny plots, regardless of edaphics. Particular species varied widely in their preferences with at least one species being an indicator for each of the six habitats, e.g.: “fan-form tubers Bryaceae” was specialized on granitic wet habitat; Grimmia lisae was specialized on granitic shady habitat; Grimmia montana was specialized on granitic sunny habitat; Didymodon tophaceous was specialized on calcareous wet habitat; Orthotrichum cupulatum + hallii was specialized on calcareous shady habitat; Grimmia anodon was specialized on calcareous sunny habitat. The composition of the bryophyte assemblages was very strongly affected by the interaction of calcareous-versus-granitic × dry-versus-wet; the wet calcareous assemblage was the most distinctive. To the extent possible, we classified the various species into guilds (e.g., the calcicolous rheophyte guild) taking into account generalization versus specialization. In summary, we found remarkable interactions between edaphics and wetness.

Recent field work in the Petersburg Borough of southeastern (SE) Alaska has led to the discovery of two species of lichenized fungi in the Ostropales that are here described as new to science: Jamesiella dacryoidea Fryday, which has green-grey dacryoid thlasidia, and Sagiolechia bairdensis Fryday, which has very small apothecia (<0.2 mm diam.), 3-septate ascospores and a trebouxioid photobiont. A key to the North American species of Sagiolechia and Gyalidea is also provided. In addition, Bryobilimbia ahlesii (Hepp) Fryday, Printzen & S.Ekman is reported for the first time from Alaska, along with records of several other species that have rarely been collected in the state.

In the course of collecting population samples of Mniaceae in southwestern China, a new species was discovered. Plagiomnium jiuzhaigouense occurred in large patches on spruce logs in forests dominated by spruce, fir and larch intermixed with deciduous hardwoods such as maples and birches at elevations between 2,500 m and 3,000 m. It appears to be most similar to P. tezukae, a Southeast Asian endemic known from Japan, Korea, and China. The new species differs in having smaller leaves, shorter leaf cells, and longer teeth composed of two or three cells. Based on sequencing of two regions of chloroplast DNA (rps4 and rpl16) and one of nuclear DNA (ITS2), P. jiuzhaigouense is placed between Section Rosulata and Section Undulata, rather than in Section Rosulata to which P. tezukae belongs. This result presents a challenge to the traditional delimitation of sections in the genus.

Reichlingia americana, a new saxicolous species, is described from Oklahoma, U.S.A., representing the first records of the genus in North America. The species is distinguished from other members of the genus by a combination of its epilithic, rimose thallus; submuriform ascospores; presence of 2′-O-methylperlatolic acid; and unique habitat on sheltered sandstone faces. Distinctions from related species are discussed and a key to members of the genus is provided.

Two new species of lichenicolous Opegrapha are described from New Brunswick, Canada. Opegrapha inconspicua was found once on a rock bluff above a river on the thallus of Verrucaria aethiobola. It is characterized by punctiform, rounded, black ascomata 75–170 µm diam., an excipulum dark brown to black only in the upper part and (1–)2(–3)-septate ascospores of (12.5–)15.5–25 × 4–5 (–5.5) µm. Opegrapha parmeliiperda was found in four localities on epiphytic Parmelia squarrosa and P. sulcata. It is characterized by short lirelliform ascomata 70–220(–250) × 70–120 µm, in ± loose groups of 5–15(–20) lirellae forming on black necrotic areas on the host thallus, 4-spored asci of 32–40 × 11–15 µm, and persistently hyaline and 3-septate ascospores of (11–)13–15.5(–17) × (3.5–)4–5(–5.5) µm. Opegrapha lamyi is reported for the first time in Canada, and O. anomea and O. sphaerophoricola for the first time in New Brunswick. One of only two previous reports of O. lamyi for the U.S.A. is based on a specimen from Colorado, revised here to Sclerococcum suburceolatum, the latter record representing a significant range extension for that species. Three of the five lichenicolous Opegrapha species reported here for New Brunswick are so far known in the province only in old mixedwood swamp-forests, highlighting the conservation significance of this forest community type. An identification key to the lichenicolous Opegrapha s.l. species known from Canada is provided. The worldwide diversity and host specificity of lichenicolous Opegrapha s.l. are discussed.

We evaluated and compared the physiological and morphological response to pollution of two epiphytic lichen species, the foliose lichen Flavopunctelia praesignis and the fruticose lichen Usnea ceratina. Lichen samples were collected at remote areas and transplanted at different distances and directions from a paper industry in Morelia (Michoacán, Mexico). Lichen transplants were exposed for 4 months (1) around the industrial area and (2) in their native habitats (control sites). Changes of total chlorophyll content between samples before and after exposure, and morphological damage in the lichen thalli were investigated. Lichens showed species-specific responses. Flavopunctelia praesignis increased in total chlorophyll content after exposure around the industrial area and in control site. This suggests that total chlorophyll changes by a seasonal effect than pollution effect. On the other hand, chlorophyll content of U. ceratina did not change significantly after exposure. Bleaching, changes in color, deformations, and necrosis of lichen thalli were better visible in U. ceratina near the paper industry. We conclude that U. ceratina is a more pollution-sensitive species than F. praesignis. Morphological damage in the lichen thalli would be a suitable indicator for monitoring early biological effects of air pollution caused by the paper industry.

Ascorbate peroxidase (APX) is an important antioxidant enzyme responsible for the conversion of H₂O₂ to H₂O and O₂. In this study, APX was studied in the widespread boreal cushion moss Dicranum scoparium. Native PAGE of crude extracts of moss thalli revealed the presence of APX isoforms in D. scoparium with a range of molecular masses. An APX complementary DNA (cDNA) gene of 771-bp length was cloned and designated as DsAPX. The cloned coding domain sequence (CDS) encoded a 256 amino acid polypeptide, and the predicted protein product was calculated to have a molecular mass of 28.4 kDa with an isoelectric point of 5.7. Several highly conserved sites important for enzyme activity were predicted using bioinformatic tools. The DsAPX protein has similarities of 91%, 78%, 67% and 66% with APX homologs from Grimmia pilifera, Physcomitrella patens, Zea mays and Nicotiana tomentosiformis, respectively. The high homology with cytosolic APX from G. pilifera strongly suggests that the cloned DsAPX gene encodes a cytosolic APX. We studied the role of APX in the tolerance of this moss to abiotic stresses. Changes in both APX activity and DsAPX gene expression, estimated using reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR), showed that the gene was up-regulated in response to desiccation/rehydration, and expression was maintained during a heat stress of +50°C. By contrast, DsAPX was down-regulated by a freezing (–20°C) treatment. Results obtained extend our knowledge of the diversity of APX isoforms that occur in bryophytes and suggest that APX may be involved in the tolerance of D. scoparium to abiotic stresses.

The taxonomy of Cinclidium, with only four species recognized, has been remarkably stable compared to most other genera of the Mniaceae. Recently, however, one new species (C. alaskanum) has been added and another (C. minutifolium) resurrected. The latter was described by Brotherus in 1929 from East Siberia and known until recently only from the type collection. Most authors have considered the species a synonym of C. latifolium, but new collections made since the 1990s from other regions of Russia have prompted reconsideration. Moreover, sequencing of three regions of the chloroplast genome of Cinclidium sampled on a worldwide basis supports the view that C. minutifolium is highly genetically differentiated from the other five species. That study also suggests that C. minutifolium might occur in Alaska. Here we confirm occurrence of this species on the North Slope of Alaska and provide drawings and keys to facilitate identification by bryologists working in other areas of the Arctic.

Analyses of data associated with 1376 taxonomic innovations (703 new taxa, 673 new combinations and replacement names) published from 2018–2020 are presented. Taxonomic contributions represented 14.2% of the published literature for the period. Most registration numbers for new names were obtained from MycoBank, suggesting the community has coalesced behind this resource. The overwhelming majority of new taxa (85.1%) and combinations (94.1%) involved crustose lichens and lichenicolous fungi. But lichenicolous fungi, regarded as a major source of undetected biodiversity, represented less than a fifth of innovations. More than half of new taxa were described from Asia and South America. Fewer than half (39%) of new taxa were published with molecular data, mostly from the ITS region but often in combination with data from additional loci. The majority of new taxa were based on small numbers of specimens (34.1% from one specimen, 69.2% from five or fewer) from few locations (44.4% from one location, 80.7% from five or fewer). Although a large number of identification keys were published, many new taxa were described with limited ecological data, distribution data or range maps, or discussion of similar species or phenotypic variation. Many innovations based on previously published names did not cite the nomenclatural type (67.7%) and less than a tenth of all such names were newly typified. Based on these results a best practices framework is presented.