The antifungal and antifeedant activity of bryophytes is widely known, but mainly from in vitro studies. The first in vivo experiments have been performed at Bonn University. Alcoholic extracts of all twenty bryophytes used had an effect on a variety of crops infected with different fungi. Two liverworts showed systemic effects. Based on these results, commercial products from bryophytes have been developed and are sold in Germany. Additional field experiments using extracts derived from native bryophyte species were successfully completed in Peru and Bolivia. Bryophyte extract also has effects on human pathogenic fungi and may cure skin diseases, but currently are not sold for that purpose. However, a patent has been obtained to cure fungal infections of horses with bryophyte extract. This same extract shows antifeedant effects against slugs.

This paper reports on a study of the isidiate corticolous species of Caloplaca in North and Central America with notes on similar species from other parts of the world. Of the 20 described isidiate species studied, five are found within the study area. The most common species are C. epiphora and C. furfuracea. Apothecia are frequently found on these isidiate species, in contrast to the sorediate species. A key to all species studied, color photographs, and distribution maps are provided. Several new synonyms are proposed. Caloplaca griseovirens and C. isidiosissima are younger synonyms of Caloplaca aphanotripta. Caloplaca hensseneana and C. neotropica are synonyms of C. wrightii. Caloplaca bassiae and C. herbidella have been reported from the study area, but do not occur here. Caloplaca bassiae is known from Africa, India, China, and Australia and is the oldest name for C. isidiosella and C. malaensis.

We measured colony growth over a three year period in the obligate epiphytic moss Neckera pennata Hedw. in three forest sites in eastern Sweden. Increment in colony area was proportional to colony size; hence area growth was modelled with the exponential growth function. Growth was measured over four periods (ca 0.5 to 1 yr long), among these periods relative growth rate varied between 0 and 35% yr⁻¹ with an annual growth rate of 13.6% for the whole studied period. Colony growth was correlated with precipitation during the periods and this relationship was used to calculate relative growth rate at normal precipitation. The regressed relative growth rate (18.2% yr⁻¹) was utilized to model average colony growth over time, from establishment to a colony size of 250 cm². The model was also used to estimate age of first reproduction, which occurred at a colony size of 12–79 cm², corresponding to an estimated age of 19–29 yr. Precipitation was the most important variable explaining colony growth, but some other factors were also of significant importance. Cover of other epiphytes surrounding the colony had a clear negative impact on growth of the N. pennata colonies, which we interpret as interference competition. Our study suggests that N. pennata was forced up the stem by stronger competitors and that growth position up to 170 cm did not impair growth. However, neither the tree species, bark pH, soil moisture, nor forest site affected colony growth, suggesting that occurrence of N. pennata was restricted by establishment rather than by growth.

Several epiphytic bryophyte species (Anomodon attenuatus, Anomodon rugelii, Brachythecium oxycladon, Leucodon brachypus, Neckera pennata, Porella platyphylloidea, and Rauiella scita) have diminished frequencies of occurrence and abundances in second-growth and partially-cut Adirondack northern hardwood forests relative to old-growth forests. The occurrence and abundances of these species, all of which exhibit mesophytic growth forms and two of which (A. attenuatus and A. rugelii) are known calcicoles, are positively correlated with diameters of sugar maple (Acer saccharum) host trees. The mechanisms causing their specificity for large, old sugar maples hosts are not known, but their distributions may reflect interactions of their respective physiological tolerances with changing microenvironmental conditions on sugar maple bark as the host trees age and mature. We tested this “gradient in time” hypothesis by transplanting mature gametophyte mats on sugar maple trees ranging from 20–85 cm diameter at breast height. Furthermore, we tested this hypothesis at two sites, a mesic and a xeric forest stand, in order to assess the influences of meso-scale (stand-level) environmental factors on the micro-scale (individual tree-level) regulation of gametophyte growth. All but two of the 96 transplants remained alive after six years. Following an initial year of overall dieback, average cover increased 23% over the subsequent five year period. Tree diameter had no effect on expansion rates of any transplanted species. Only one species, Neckera pennata, exhibited significantly greater expansion at the mesic site than at the xeric site. Our data suggest that age-related changes in microenvironmental conditions of sugar maple bark do not have an important influence on the distribution of these “large-maple” epiphytes. Rather, factors such as dispersal limitations or establishment requirements of protonemata probably limit their distribution. Additional, well-replicated transplant experiments are required to determine the effects of micro- and meso-scale environmental variation on the establishment, growth, and reproduction of epiphytic bryophytes. We discuss implications of our results for restoration of epiphytic bryophyte communities in heavily disturbed forest landscapes.

Pohlia bolanderi (Lesq.) Broth. is reported for the first time for Europe from the south of Spain (Sierra Nevada range). A description from European material is provided and differences from closely related species, with which it has been confused, are discussed. It is also known from alpine regions in western North America, including British Columbia, Washington, Oregon, California, and Nevada.

The genus Philonotis is generally considered taxonomically difficult because of high levels of phenotypic variation and frequent intergradation between species. Philonotis fontana and P. caespitosa, two poorly understood taxa that appear to be widespread across Europe and North America, are difficult to distinguish and some authors consider them two varieties of one species or even synonyms. Isozyme variation at 13 putative loci among 22 European samples representing these two species indicates that the two taxa are genetically distinct although closely related (Nei's genetic identity = 0.84). In a second part of the study, ten individuals were sampled from each of four populations from the Czech Republic; one population was clearly P. fontana (based on morphology), one was P. caespitosa, and two populations were morphologically aberrant and could not easily be assigned to one species or the other. This second study tested alternative hypotheses that the intermediate phenotypes reflect morphological plasticity, or that they result from interspecific hybridization. The results corroborate genetic differences between P. fontana and P. caespitosa, but the two morphologically aberrant populations contained alleles from both species. Plants in one of the morphologically aberrant populations were more distinct genetically from both P. caespitosa and P. fontana than were the two species from one another. The other morphologically aberrant population could be viewed as either intermediate between the two species in terms of its isozymes, or it could be included in a broadly circumscribed P. caespitosa. The results are consistent with interspecific hybridization, although phenotypic plasticity probably also contributes to morphological variation.

We studied epiphytic macrolichen communities in northern and central California to 1) describe how gradients in community composition relate to climate, topography, and stand structure and 2) define subregions of relatively homogeneous lichen communities and environmental conditions. Non-metric multidimensional scaling was used to characterize landscape-level trends in lichen community composition from 211 plots. We found two gradients in lichen community composition that corresponded with macroclimatic gradients: one correlated with temperature variables and elevation, the second with moisture variables. Moist, warm plots supported more cyanolichen species, while warm but dry plots supported a diverse nitrophilous flora. Ammonia pollution, which was not accounted for in the analysis, may also explain spatial patterns in nitrophilous species and deserves further study. Cluster analysis and indicator species analysis were used to divide lichen communities into more homogeneous groups and identify group indicator species. Three groups of plots differing in geography, macroclimate, and community composition were defined: the Greater Central Valley group; the Sierra, Southern Cascades, and Modoc group; and the NW Coast group. Communities in the Greater Central Valley group were typically diverse and dominated by nitrophilous species, averaging 14 species and 40% nitrophiles. Cyanolichens common to this group were mainly diminuitive species from the genera Leptogium and Collema. Indicator species strongly associated with the Greater Central Valley included Melanelia glabra, Candelaria concolor, and Parmelina quercina. Communities from the Sierra, Southern Cascades, and Modoc group had the lowest species richness and total lichen abundance. Cyanolichens were absent, while nitrophiles such as Candelaria concolor and Xanthoria fulva were frequent. Indicator species included Letharia vulpina, L. columbiana, and Nodobryoria abbreviata. The NW Coast group had the highest species richness, cyanolichen diversity, and cyanolichen abundance while nitrophiles were rare. Indicator species included Platismatia glauca, Esslingeriana idahoensis, and Cetraria orbata.

A comparison between lime (Tilia platyphyllos) and holly oak (Quercus ilex) as substrate trees for epiphytic lichens was carried out in Siena (central Italy). The purpose of this study was to investigate the influence of these phorophytes on the diversity of epiphytic lichens, at a similar climatic regime and at the same air pollution status. The diversity values measured on Tilia were on the average 1.5 times higher than those on Quercus. No difference between the two tree species appeared for bark pH and bark concentrations of NO₃⁻, SO₄²⁻, NH₄ , Cu, and Pb. Bark concentrations of Mn were higher for Quercus. The water-holding capacity of the bark of Tilia was higher than that of Quercus. The amount of incident light radiation was similar for the two trees in summer, when both species have leaves, but was higher on deciduous lime in winter, when only the evergreen Q. ilex has leaves. Influx light in winter is the most important factor for determining differences in the biodiversity of epiphytic lichens on Tilia and Q. ilex.

Spatial segregation of the sexes in bryophytes has been implicated as the primary reason for the lack of sporophyte production in many dioicous bryophyte populations. Additionally, sex-specific microhabitat specialization by dioicous bryophytes may influence population sex ratios and the maintenance of sexually dimorphic traits. We examined habitat use of female and male M. inflexa in two populations in Trinidad and 10 populations in the U.S.A. to determine whether the sexes were spatially segregated within populations and if the sexes specialized on different microhabitats. Populations differed in habitat characteristics, sex ratios varied among populations, and populations consisted mainly of single-sex or non-sex-expressing patches of plants. Despite the fact that Marchantia inflexa is sexually dimorphic, female and male plants used areas of similar substrate, humidity, wind speed, and exposure within and among populations. In U.S.A. populations, males were found in areas with more open canopy and used a wider range of light environments than females. Although the sexes of M. inflexa were spatially separated within populations, they overlapped in habitat use and their distributions were not correlated with an environmental gradient.

Dactylospora aeruginosa Holien & Ihlen, sp. nov. is described from Norway and U.S.A. and D. borealis Holien & Ihlen, sp. nov. is described from Norway, Sweden, and U.S.A. Both species are lichenicolous, but D. aeruginosa is also saprobic on wood and bark of Picea abies and Juniperus communis, whereas D. borealis is only rarely growing on bark of P. abies. Notes are given on their ecology and distribution. A key to the known lichenicolous species of Dactylospora occurring in Scandinavia is included. Lichenodiplis lecanorae is suggested to be the anamorph of D. borealis.

Isopterygium tenerum (Sw.) Mitt., a species previously considered restricted to the New World, is reported for the first time from the Old World. Examination of the type collections of three South African species that were given names under Plagiothecium and Isopterygium, namely Plagiothecium rhynchostegioides Müll. Hal., P. sphagnadelphus Müll. Hal., and Isopterygium brachycarpum Dixon, revealed their conspecificity with I. tenerum. Accordingly, this species is established as one more Afro-American disjunct species. Some gametophytic structures of the type specimens of the South African species are illustrated.

Climacium dendroides (Hedw.) F. Weber & D. Mohr is reported new to Mexico and in the first known locality in the tropics, at the elevation of 3,000 m, on the ancient shield volcano of Cofre de Perote. Variation in branching of the costa is assessed in this plant and in material of C. dendroides worldwide. Additional taxa of interest from this locality on Cofre de Perote include Aulacomnium palustre and Polytrichum commune (both new to the state of Veracruz).

Diagnoses are given for Braunia alopecura (Brid.) Limpr. and B. delavayi Besch. A key to two species of Braunia in China is provided. Braunia obtusicuspis Broth. is synonymized with Hedwigidium integrifolium (P. Beauv.) Dix.

Codriophorus corrugatus Bednarek-Ochyra is described and illustrated as a species new to science. It is closely related to C. anomodontoides (Cardot) Bednarek-Ochyra & Ochyra and C. fascicularis (Hedw.) Bednarek-Ochyra & Ochyra from which it differs in its long subulate, often serpentine leaf acumen which is distinctly corrugate or ruffled in the upper part and markedly cristate or papillose-crenulate at the apex; much longer peristome teeth; and its costa that extends to about mid-leaf and is bistratose in transverse section and flat on the ventral surface. Codriophorus corrugatus is an east-Asian northwestern North American, disjunct, boreal-montane species known from southern Alaska in North America; Yakutia in Arctic Russia; Kamchatka in the Russian Far East; Sichuan, Quinghai, and Shaanxi provinces in China; and Hokkaido in Japan.

The unique ability to perform targeted gene disruption in mosses has made Physcomitrella patens an attractive choice for plant functional genomics. A cDNA ALDH11A5 (AY504666) was identified in the plant P. patens with significant similarity to the cytosolic NADP -dependent, non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase (GAPN; EC 1.2.1.9). RNA blot hybridization was used to analyze ALDH11A5 mRNA transcript abundance in response to a variety of stresses including high osmoticum (600 mM sorbitol), salinity (300 mM NaCl), and ABA application (50 μM). This is the first report of GAPN from bryophytes, and demonstrates that this unique plant enzyme is not restricted to tracheophytes.

Staurolemma carolinianum is described as the first species from the American continent of this apparently ancient genus. The type was collected on Juniperus on sand dunes of coastal North Carolina, and this easily overlooked species may be present in similar habitats southwards to Florida. Its closest relative, S. dussii (Vain.) P. M. Jørg. & Henssen, is known from the West Indies, and the genus shows a Madro-Tethyan distribution pattern.