Bryophytes (including mosses, liverworts and hornworts) are a heterogeneous group of terrestrial plants, which comprise over 24,000 species worldwide. Given the various biological activities reported from bryophytes, they have a huge commercial potential. Due to their minute size and rather small biomass in various ecosystems, bryophytes are a seldom part of ethnomedicine and rarely subject to medicinal and chemical analyses. Still, hundreds of novel natural products have been isolated from bryophytes. Bryophytes have been shown to contain numerous potentially useful natural products, including polysaccharides, lipids, rare amino acids, terpenoids, phenylpropanoids, quinones and many other specialized metabolites. Additionally, different bryophyte extracts and isolated compounds have shown antimicrobial, antiviral, cytotoxic, nematocidal, insecticidal, effects on smooth and non-striated muscles, weight loss, plant growth regulators and allelopathic activities. Bryophytes also cause allergies and contact dermatitis. All these effects highlight bryophytes as potential source for herbal remedies and production of chemicals to be used in various products.

Fossil tree resins preserve a wide range of animals, plants, fungi and microorganisms in microscopic fidelity. Fossil organisms preserved in an individual piece of amber lived at the same time in Earth history and mostly even in the same habitat, but they were not necessarily parts of the same interacting community. Here, we report on an in situ preserved corticolous community from a piece of Miocene Dominican amber which is composed of a lichen, a moss and three species of leafy liverworts. The lichen is assigned to the extant genus Phyllopsora (Ramalinaceae, Lecanoromycetes) and is described as P.magna Kaasalainen, Rikkinen & A. R. Schmidt sp. nov. The moss, Aptychellites fossilis Schäf.-Verw., Hedenäs, Ignatov & Heinrichs gen. & sp. nov., closely resembles the extant genus Aptychella of the family Pylaisiadelphaceae. The three leafy liverworts comprise the extinct Lejeuneaceae species Cheilolejeunea antiqua (Grolle) Ye & Zhu, 2010 and Lejeunea miocenica Heinrichs, Schäf.-Verw., M. A. M. Renner & G. E. Lee sp. nov. and the extinct Radulaceae species Radula intecta M. A. M. Renner, Schäf.-Verw. & Heinrichs sp. nov. The presence of five associated extinct cryptogam species, four of which belong to extant genera, further substantiates the notion of a stasis in morphotype diversity, but a certain turnover of species, in the Caribbean since the early Miocene.

Quantitative analyses of the factors driving the distribution of bryophytes in the phyllosphere of tropical rain forests are rare. In this study we sampled epiphyllous bryophytes on two leaves of each of 57 individuals belonging to four phorophyte species (Asplundia pittieri, Carludovica drudei, Costus laevis and Dieffenbachia concinna) at three adjacent, but microclimatically varied sites in the Esquinas forest, Costa Rica. Microclimatic parameters and phorophyte identities were correlated to differences in cover, diversity and species composition of bryophyte assemblages by means of Kruskal–Wallis tests, non-metric multidimensional scaling and indicator species analysis. High relative humidity and in particular daily fluctuations in relative humidity proved to be the most important factors for epiphyll distribution suggesting severe constraints of epiphyll colonisation by pronounced humidity fluctuations. Differences in air temperature and light availability as well as phorophyte identity were only weakly correlated with bryophyte cover and diversity. However, species composition of epiphyllous assemblages was related to all microclimatic variables as well as to phorophyte identity. The strong response of epiphyllous bryophytes to even subtle microclimatic variations suggests that undisturbed forest canopies and their control on microclimate may be essential for the development of epiphyll communities.

Input from molecular phylogenetics in the past five years has substantially altered concepts of systematic relationships among liverworts. While these studies have confirmed the monophyly of phylum Marchantiophyta, they have demonstrated that many previously recognised ranks within the hierarchy are unnatural and in need of modification. Changes in the ranks of suborder and above have been proposed by various workers, but modifications in the circumscription of genera and families are still required. A comprehensive, phylogenetic classification scheme that integrates morphological data with molecular hypotheses is presented. The scheme includes diagnoses and publication citations for all names above the rank of genus. All currently recognised genera are listed alphabetically in their respective families; subfamilies are not indicated. Major modifications and novel alignments of taxa are thoroughly discussed, with pertinent references provided. Jungermanniaceae is redefined and Solenostomataceae fam. nov. is formally described to accommodate some of the genera excluded from it.

Mannia controversa (Meyl.) Schill comb. nov. (Marchantiidae, Aytoniaceae), a long-forgotten European taxon, is fully redescribed and a lectotype selected. It is reported from its original localities in the Swiss Alps and new sites in the Austrian and French Alps. A series of specimens from eastern Asia are closely related and are described as Mannia controversa subsp. asiatica Schill & D.G.Long. For the species, differences with other Mannia species are summarised and for its two subspecies, descriptions, illustrations (including SEM images) and a key are provided along with notes on ecology and distribution maps.

Recent studies on molecular phylogeny of complex thalloid liverworts (Marchantiopsida) have revealed the need to recognize four new higher taxa: Family Neohodgsoniaceae, Order Neohodgsoniales, Order Lunulariales and Family Dumortieraceae. These are formally described along with notes on their differences from other complex thalloid liverworts.

Deception Island in the South Shetland Islands is one of the most volcanically active sites south of 60°S. Between 1967 and 1970 three major eruptions devastated large expanses of the landscape and its vegetation. Since 1970 extensive recolonization has occurred on the more stable surfaces. Unheated ground supports several bryophyte and lichen communities typical of much of the Maritime Antarctic, but geothermal habitats possess remarkable associations of bryophytes, many of which are unknown or very rare elsewhere in the Antarctic. Nine geothermal sites and their vegetation are described. Communities associated with more transient sites have disappeared when the geothermal activity ceased. Mosses and liverworts occur to within a few centimetres of the vents where temperatures reach 90–95°C, while temperatures within adjacent moss turf can reach 35–50°C or more and remain consistently between 25 and 45°C. Most of the bryoflora has a Patagonian–Fuegian provenance. It is presumed that, unlike most species, the thermophiles are not pre-adapted to the Antarctic environment, being able to colonize only where the warm and humid conditions prevail. The floristic and ecological importance of these thermophilic communities, and their sensitivity to perturbation by the rapidly increasing annual summer influx of tourists, as well as scientists, has resulted in these unique sites being proposed as components of a new Antarctic Specially Protected Area under the Antarctic Treaty.