DNA sequencing techniques and molecular and phylogenetic analyses have developed rapidly over a short time, finding application in fields across biology and medicine. The field of lichenology is no exception, with hundreds of studies utilizing DNA sequences to reconstruct phylogenies and uncover the evolutionary histories of populations and species. Given the dramatic advancements of sequencing technologies, analytical techniques and computational capabilities, an assessment of trends in molecular lichen research is timely. We present a literature meta-analysis that reviews the existing published molecular and phylogenetic research using traditional (e.g., Sanger) and next-generation (e.g., Illumina) sequencing technologies. Specifically we (i) determine how molecular data have been applied to lichens thus far, (ii) document and discuss trends in sequence data application, (iii) examine taxonomic representation and biases at the family level, and (iv) outline avenues of future research as well as highlight areas where targeted study is urgently needed.

We investigated the seasonality of the development of gametangia and sporophytes of Racomitrium lanuginosum at a snow-free site (ca. 645 m on Mt. Mihara) and compared it with a seasonally snow-covered site (ca. 2200 m on Mt. Fuji) to clarify the effects of the length of growth period regulated by snow cover. The number of inflorescences and the number, size and developmental stages of male and female gametangia and sporophytes were recorded once every month from March 2014 to February 2015. At the snow-free site, archegonia rapidly developed in spring, but antheridia took longer to develop from the late summer; sperm dispersal mainly occurred in winter. Spore dispersal occurred from winter to summer and fertilization occurred in spring. Some notable phenological patterns were observed at the snow-free site, such as the discordance of the timing of maturation between male and female gametangia, and the occurrence of spore dispersal in winter. These results suggest that the snow-free site is close to the limit of successful sexual reproduction and that snow cover is an essential factor to maintain the phenological patterns of this species.

Microlejeunea ocellata (Herzog) Grolle was originally recognized as Rectolejeunea ocellata Herzog, a very enigmatic species known only from Australia and New Zealand. The systematic position of this species has been controversial owing to a number of interesting characters. A monospecific subgenus, Rectolejeunea subg. Notholejeunea R.M.Schust. was previously established to accommodate this species. Our molecular phylogenetic and morphological evidence reveals that this species represents a separate genus. Here we propose a new generic name, Cumulolejeunea, because recombining subg. Notholejeunea R.M.Schust. at generic rank is blocked by the earlier Notholejeunea Kuntze of 1903.

The species Psoroma spinuliferum is described here as new to science. It is only known from the holotype on a Picea sitchensis trunk near a sea-shore in southern, coastal Alaska. The species is distinct in having short, brittle, spinule-like hairs on both apothecium margins, thalline squamules and on pulvinate to coarsely coralloid cephalodia with emerald-colored Nostoc photobionts. These spinules are unique within Pannariaceae as they are developed on both the chlorobiont and on one of two cyanobionts, but it is uncertain whether they can act as vegetative propagules. The presence of two types of cephalodia is also unique within Pannariaceae. The second type consists of glabrous, small-foliose, geotropically arranged cephalodia, containing a Nostoc strain with cells of an intense ultramarine color, when observed after long storage. The species also has shorter ascospores than Psoroma paleaceum, another hairy species. The hair types of Psoroma hypnorum and P. paleaceum are here by contrast referred to as tomentum and scales, respectively.

In this study we provide the first record of bryophyte community diversities in contrasting habitats of the Torngat Mountains National Park (Labrador, Canada), a coastal mountain subarctic ITEX (International Tundra Experiment) study site. The point-intercept method was used to describe and track changes in the bryophyte community diversity (cover, species richness, diversity indices) at dry vs. wet habitats, in 2008 and 2010. The majority of species observed are common and abundant to the Canadian polar region. Bryophyte community composition differed between wet and dry habitats; Racomitrium lanuginosum, Polytrichum piliferum and P. juniperinum dominated dry and exposed habitats, whereas Drepanocladus spp., Aulacomnium spp. and Sphagnum spp. dominated wet habitats. Wet habitats were more diverse (4.8 ± 2.9 vs. 1.6 ± 1.2 species m^–2) and had higher bryophytes cover (66.1 ± 35.4% vs. 12.6 ± 9.9%) compared to dry habitats. A survey of the tundra change literature, suggests that a warming climate will decrease bryophyte cover as shrub cover increases, and that the cover of certain species (e.g., Polytrichum piliferum) will likely increase in dry habitats where shrub cover is not expected to increase to the same degree.

A new species, Tortula neoeckeliae C.Feng & J.Kou, is described and illustrated from Guizhou Province of China. It is characterized by oblong-ovate to lingulate and unbordered leaves with broadly acute to rounded and awned apex, broadly revolute margins, long-excurrent costa with dorsal stereid band 1–2 cells thick, smooth or very sparsely hollow-papillose lamina, erect, nearly straight and exerted capsules with peristome of 32 strongly twisted filaments. The Chinese specimens previously assigned to Tortula transcaspica Broth. proved to belong to T. neoeckeliae, so that the report of T. transcaspica from China is erroneous. The new species is contrasted with similar species in Tortula and a key to Chinese species of the genus is provided.

While regarded as a principal factor of desiccation tolerance in bryophytes (along with rate of drying, water content and duration dry), the rate of rehydration has been broadly neglected or inadequately assessed. Prior to receiving liquid water from a rain event, desiccated bryophytes are able to partially rehydrate their tissues by absorbing water vapor when ambient relative humidity is high, a process known as prehydration. A single clone of Syntrichia norvegica was cultured for 4–6 months in a suprasaturated condition. Shoot apices were used in experimental prehydrating (1–48 h), drying (5 min–300 h, equilibrating at ∼0% relative humidity), and duration dry (0–42 d continuously dry at 54% RH) series. Shoots were subsequently prehydrated 24 h prior to exposure to liquid water or directly immersed in liquid water and assessed for desiccation associated damage. Prehydration occurs over a 4-h period, after which shoot water content levels out. Shoots that normally die when equilibrated at low water contents were rescued with a prehydration treatment. At extremely rapid rates of drying (<20 min) prehydration effects were limited. However, at gradual rates of drying the prehydration treatment restored chlorophyll fluorescence and regeneration capacity to near control levels. Prehydration also improved the capacity of a shoot to recover following continuously dry episodes of several weeks. Without a prehydration treatment, shoot apices of the moss Syntrichia norvegica were killed by desiccation to equilibrium with 0% RH, and severely damaged upon rehydration from a 42-d dry period. With a prehydration treatment, both of these scenarios were mitigated. For the prehydration treatment to be effective, a rate of drying only of 30 or more minutes from full turgor without external free water to leaf curling achieves a significant lessening of damage.

The occurrence of terrestrial mosses in temperate deciduous forests is limited by abundant leaf litter that covers almost all of the soil, except along stream banks where mineral substrates are exposed by wind. However, stream banks are also subject to erosion that is a major disturbance for moss populations. Utilizing transplants and observations over a three period (2015–2017), we examined maintenance of current populations and establishment of new ones along the banks of two headwater streams, one in Virginia (Meadowood) and one in Illinois (Vishnu). Of the 224 plots, some with and some without mosses, that we monitored at the two stream study areas, 78 (35%) were lost to erosion or stochastic events. Areas with established moss populations had similar losses than areas without mosses (43% lost vs. 39% lost); however, losses at the two sites were very different—in Illinois, 41% of the original plots were lost, compared to 29% in Virginia. These differences in losses from erosion correspond to 32% greater number of high (>2 cm) and extreme (>4 cm) precipitation events at the Illinois site. In general, areas with mosses were lost at the same rate as those with leaf-covered bare soil. Leaf cover of moss plots, measured at height of the autumn leaf fall, averaged 12% at the Illinois site and 14% in Virginia, compared to plots without mosses that averaged 56–57% leaf cover, indicating that established moss populations are associated with exposed microsites, whereas microsites without mosses have high leaf cover. We examined the potential for colonization of new sites using transplants. Mosses transplanted onto bare soil successfully established 52% of the time, with unsuccessful ones mostly lost due to high leaf cover. Bare areas that did not receive transplants were colonized only 14% of the time, while bare areas within established moss populations were recolonized 48% of the time. We conclude that: 1) stream bank bryophyte populations are limited by leaf litter on the forest-side and erosion on the stream-side—the latter influenced by high precipitation events; 2) new potential habitats are often covered by leaf litter prohibiting establishment; 3) establishment of new populations in the local area appear to also be limited by availability (or dispersal) of diaspores; and 4) despite these limitations, losses from erosion appear to be counter-balanced by persistence and slow expansion of existing populations that remain largely litter free owing to slightly raised canopy surfaces and rapid recolonization of internally disturbed microsites.

Toninia tecta, a non-lichenized obligately lichenicolous fungus, is described new to science. The species is known from several sites in midcontinental North America. Toninia tecta has an endokapylic thallus with dark superficial apothecia restricted to the sheltered undersides of thalli of saxicolous umbilicate species of Dermatocarpon. The new species is characterized by 3-septate ellipsoid ascospores, elongate filiform conidiospores, a reddish brown hypothecium and grey to greenish epithecium that reacts KOH–, HNO₃ violet. Features of the species are compared with those of other lichenicolous taxa in the genus.