Pohlia robertsonii is newly described from central California. Plants with polysetous sporophytes immediately separate this species from all other members of the genus Pohlia in North America. Pohlia robertsonii is further characterized by firm, but not thickened leaf cells, paroicous inflorescences, long, narrowly cylindric capsules, and irregular peristomes in which the endostome segments equal or exceed the exostome teeth, and lack cilia. The peristomial formula is 4:2:2–4. Pohlia rabunbaldensis is described from the southern Appalachian Mountains of Georgia and North Carolina. The slender gametophytes bear single bud-like gemmae in upper leaf axils. The dull leaves that are somewhat shriveled on drying resemble those of P. annotina, but the large single gemmae with flexuose, broadly laminate leaf primordia resemble those of P. drummondii. The conspicuously decurrent leaves distinguish P. rabunbaldensis from both previously known species.

Spatial variation in population sex ratios is common in bryophytes, but the ecological correlates of this variation are not well documented. The dioecious desert moss Syntrichia caninervis presents an example of this variation occurring at the regional scale (kilometers) as well as the microscale (centimeters). Here, our goal is to correlate variation in plant traits and sex expression levels to relevant ecological variation, and specifically to investigate whether spatial segregation of the sexes (SSS) exists at the level of the patch. Five sporophytic patches of S. caninervis were sampled at 10 cm intervals along a transect extending from shrub understory into the exposed intershrub region, thus representing a stress gradient of light intensity and moisture availability. Along a gradient from understory to intershrub microsites, individual plant length and biomass declined significantly, with plants under the canopy twice as large as those in the more exposed microsites. Sex expression declined from 76% under the shrub canopy to < 5% in the intershrub region, with the number of inflorescences per individual declining from 1.5 to near zero along this transect. Of the 778 individuals sampled, only 11 males were recovered, and all of these males occurred within 15 cm of the shrub canopy line. Nevertheless, the high number of female and nonexpressing individuals coupled with a rarity of male individuals resulted in no association between gender and microsite. However, using the distribution of fertilized female inflorescences as a surrogate measure of historical male presence indicated that males were significantly clustered near the shrub canopy line, indicative of spatial SSS. We hypothesize that males are less stress tolerant than females and that this condition may be an outgrowth of the sexes allocating differential resources to sexual reproduction.

Genetic structure and diversity were studied in the endangered peatmoss Sphagnum angermanicum Melin to assess its conservation status. In total, 128 shoots from eleven populations throughout its Swedish distribution were analyzed. Among these shoots 28 haplotypes were identified by 19 ISSR loci. The most common haplotype (50% of the sampled shoots) occurred in all populations. The level of gene diversity over loci was intermediate compared to records from most other bryophytes. There was no genetic isolation between the populations and most of the genetic variation was found within populations. This implies either that the populations have originated from only a few common individuals or a high gene flow between populations. A relict population model is suggested to explain the observed pattern. Just after the last glaciation, S. angermanicum may have expanded its range when suitable habitat became available after the glacial ice retreated. Since then, habitats have vanished or fragmented and today only a few relict populations exist. This dioicous species has only once been reported with sporophytes in Scandinavia in modern time, but according to the genetic data, both the low level of linkage among loci and the estimated rate of recombination show evidence of sexual reproduction. However, reproduction may have been more frequent in the past. Based on the current knowledge of the species habitat requirements, life history, and the small population sizes, we conclude that the species will have an uncertain future in Sweden.

Five chloroplast coding and non-coding regions, one mitochondrial gene and its associated intron, and part of one nuclear ribosomal gene were sequenced, giving a total included aligned length of 7,845 bp. Samples from six collections, representing five species of Jensenia from South America, Malaysia, and New Zealand, four collections belonging to three species of Pallavicinia and one collection of Podomitrium phyllanthus comprised the ingroup, which was rooted on Symphyogyna marginata. Phylogenetic analysis under the maximum parsimony and maximum likelihood criteria support Jensenia as monophyletic. Within Jensenia, two monophyletic clades are resolved, one comprising the four Latin American collections and the other, the Malayasian and New Zealand species; however, this is based on only 16 parsimony informative characters. The lack of informative characters within Jensenia suggests that the divergence among taxa is relatively recent, rather than Gondwanan, as has been hypothesized based on geographical distribution. A corollary of this is that the present day distribution of Jensenia is likely the product of dispersal rather than vicariance.

The hepatic genera Colura and Pleurozia show trap-like structures in the water sacs of their leaves. The function of these structures usually has been interpreted as water storage, although zoophagy has also been suggested. The experimental evidence that a species of Colura was able to trap protozoa was presented some years ago. Therefore the trap-like structure in the water sacs of Pleurozia purpurea has been studied. It is described and illustrated by light and electron scanning microscopy. Feeding experiments revealed that the structures in the water sacs of Pleurozia purpurea are able to trap individuals of Blepharisma americana (Ciliata). This provides evidence that the lobules of this second hepatic genus function in zoophagy. Other experiments have shown that individuals of Blepharisma are attracted by plants of Pleurozia, although the exact reason for this behavior is not known. Observations in the field revealed a high percentage of lobules filled with various small animals and suggest that these are regularly trapped and not present by chance.

The neotropical moss Syntrichia bogotensis (Hampe) R. H. Zander is reported for the first time for Macaronesia on the basis of six collections from Madeira Island (Portugal). This species has previously been known only from tropical America. The principal distinctive characters that separate it from the two nearest species, S. andicola and S. norvegica, are discussed. The species is illustrated, its distribution is mapped, and its name lectotypified. A key to the Madeiran taxa of Syntrichia is provided.

A new metabolite, toensbergianic acid, was isolated from the lichen Lepraria toensbergiana Bayerová & Kukwa together with the depside, atranorin. GC/MS analyses suggest that toensbergianic acid is a diastereoisomer of roccellic acid.

The genus Hypnodontopsis is represented by three extant species, all with a very limited distribution. One was described as H. mexicana (Thér.) Robins., only known from single localities in Mexico and Uganda, another is H. apiculata Iwats. and Nog., only known from a small area in Japan, and the last is H. spathulata H. Akiyama and A. Tanaka, recently described from Burma. The genus was, however, present in the Eocene (ca 45–58 myr bp) with five species; one of which is identical to the extant H. mexicana and is the most common moss in Baltic amber. All fossil species are illustrated and described. They are distinguished by variation of character states such as apiculate, lingulate, and piliferous leaves. The fact that the genus consisted of five (known) species in Tertiary, some of them very common, but only three extant species, which are quite rare, shows a decline of species number and frequency.

Bryum capillare, a moss of worldwide distribution, is ubiquitous to cities where it is commonly found growing within the cracks of sidewalks. Because of its occurrence in the harsh and depauperate urban environment, it was hypothesized that this moss is resistant to the deleterious effects of pollutants, such as acid rain. We tested this by measuring the growth response of an axenic culture line of B. capillare to simulated pH-adjusted rain. Field and experimental data both suggest that B. capillare is not especially resistant to acid rain. In the first experiment B. capillare protonematal cultures were subjected to simulated rain at pH levels between 3 and 8. Cultures at pH 4.0 simulated rain resulted in an approximate 50% reduction in colony area from that obtained in the pH 8.0 treatment. Therefore, we would expect the acid rain in Washington, DC to be unfavorable to the growth of B. capillare. Yet, the moss is both common and abundant in the city. In a second experiment the optimal pH for the in vitro culture of B. capillare ranged between 6 and 8. This helped explain its abundance in the city since soil pH samples averaged 7.5. We attributed the near neutral pH of soil under B. capillare colonies to its parent substratum: cement. In a third experiment, the adverse effects of simulated acid rain on B. capillare, were reversed by culturing the moss on cement-amended medium (pH 7.6). Based on these experiments and on the pH values of soil and rain samples, we concluded that B. capillare is protected from adverse effects of acid rain by the apparent buffering and neutralizing capacity of its preferred substrate, the cement of city sidewalks.

Using data from randomly-selected surveys, historic locations, and ‘purposive’ surveys of likely habitats, fifteen rare epiphytic lichens (Bryoria pseudocapillaris, B. spiralifera, B. subcana, Erioderma sorediatum, Heterodermia leucomela, Hypotrachyna revoluta, Leioderma sorediatum, Leptogium brebissonii, Niebla cephalota, Pannaria rubiginosa, Pseudocyphellaria perpetua, Pyrrhospora quernea, Ramalina pollinaria, Teloschistes flavicans, and Usnea hesperina) were assessed for frequency and distribution on publicly owned lands along the immediate Pacific coast from the Canadian border south to San Francisco and for association with late seral forests and federally protected lands. A total of 178 sites of 0.04 ha each were surveyed in 2000 and 2001; 129 were randomly selected. The major distribution patterns were CA and OR coastlines ± Puget Sound, OR and WA coastlines, and OR and WA Coast and western Cascades Ranges, following major regional climatic gradients. Frequency varied considerably by state, all lichens except P. quernea were rare in at least one state (no detections among randomly selected survey sites). Odds ratio tests provided suggestive evidence that most populations of U. hesperina are in forests > 80 years old, and good evidence that forest age is not an important predictor of occurrence for R. pollinaria and H. leucomela. Ten of the target species were associated with ≤ two federally protected land allocations, and none were primarily found on protected allocations. Therefore actions on unprotected state and federal lands in the 21st century will influence persistence. Target populations for conservation are discussed.

Some additions and corrections to the recent treatment of this family in North America are made. The new species, Fuscopannaria convexa P. M. Jørg,. is described from hypermaritime Alaska. From this region, the hairy subantarctic Psoroma hispidulum Nyl., is recorded as new to North America. Fuscopannaria laceratula (Hue) P. M. Jørg. and Psoroma tenue Henssen are shown to have a wider distribution than previously anticipated, the latter arctic-alpine. Fuscopannaria labrata, a sorediate species, is described as new from maritime cliffs on the Channel Islands, California. The subtropical species Pannaria malmei C. W. Dodge, was incorrectly recorded from North America, and the material is renamed Pannaria rubiginella P. M. Jørg. & Sipm., a species recently described from Juan Fernandez in Chile. The new combination, Santessoniella crossophylla (Tuck.) P. M. Jørg., is made. A key to the two terricolous, Arctic species of Fuscopannaria containing green algae, F. globigera Fryday & P. M. Jørg. and F. viridescens P. M. Jørg. & Zhurbenko, is given.

Bryophytes are an important plant group with long-term dominance in alpine habitats. The alpine environment is however severe, and may restrict variation in bryophyte life history. This study examines the relationship between frequencies of bryophyte species and their life history traits between and within two alpine environments that differ in important environmental variables identified for bryophytes: 1) an oceanic region, with humid acidic soils (Setesdal) and 2) a sub-continental region, with more dry, productive, base-rich soils (Hol). A comparison between regions showed a higher frequency of base-demanding bryophytes in the sub-continental region. Sexual reproduction was more common among bryophytes in the oceanic region and these species also had higher indicator values for oceanic conditions and temperature as expected. Several life history traits were strongly correlated with bryophyte frequencies in the oceanic region—local species abundance increased in relation to shoot longevity, dioicism (mainly vegetative reproduction), and high humidity indicator values, but decreased for species with asexual propagules (gemmae). No traits were correlated with bryophyte frequencies in the sub-continental region. The importance of life history traits in the oceanic region indicates that severe environmental factors override bryophyte community heterogeneity only in the oceanic, acidic region. A possible explanation for higher environmental stress favoring tolerant long-lived species with vegetative reproduction could be higher grazing pressure, which is also reflected in significantly lower cryptogam coverage and correspondingly larger area of open soil in the oceanic region.

The Gyalectaceae are a family of lichenized ascomycetes of worldwide distribution from temperate to tropical regions that share a general type of hemiangiocarpous ascoma ontogeny and apothecia having a pseudoparenchymatic excipulum proprium. The genus Coenogonium (including Dimerella) has been included in the Gyalectaceae, but varies from the remaining species of this family in apothecial ontogeny and anatomy, spore size and septation, thallus and pycnidial anatomy, and ascus ultrastructure. To determine the relationships between Coenogonium and other genera in the family, ascoma ontogeny and various anatomical characters were investigated in detail. Although the ontogeny of both the genus Coenogonium and the Gyalectaceae s. str. is hemiangiocarpous, the development of the apothecia of Coenogonium and the resulting apothecial anatomy are remarkably different. Ontogenetic, anatomical, and morphological evidence supports the re-establishment of the monogeneric family Coenogoniaceae (Fr.) Stizenb.

A collection of Hong Kong lichens in the Farlow Herbarium (FH) resulting from the United States North Pacific Exploration Expedition (1853–1856), and mainly collected by Charles Wright, has been examined with regards to two recently published papers, 12 species new to Hong Kong and almost all of the 46 species listed pre-date the earliest first records for Hong Kong. A new microthelioid lichen, Distothelia isthmospora Aptroot gen. et sp. nov., is described and a new combination, Pyrrhospora chlororphnia (Tuck.) Aptroot & Seaward comb. nov., is proposed.

Protonemata of three mosses (Bryum rubens Mitt., Campylopus introflexus (Hedw.) Brid,. and Polytrichum formosum Hedw.) were exposed in sterile cultures to low concentrations of the bracken herbicide asulam, added to the solidified growth medium. Protonemata were either exposed for 24 hours and then transferred onto media without asulam, or exposed constantly to the asulam media. Growth was measured over a three-week period as the mean of two plug diameters, and development of leafy gametophores was noted. A 24-hour exposure period to asulam had no effect on the growth or development of the mosses at concentrations of 0.001–1 g a.i. (active ingredient) l⁻¹. The growth and development of all three species was significantly affected by continuous exposure to asulam at concentrations of 0.01 g a.i. l⁻¹ and above. Dose-response curves were fitted to the data and EC₅₀ values calculated. Campylopus introflexus was the least sensitive species tested and P. formosum the most sensitive, with a 10-fold difference in sensitivity between the two. The sensitivity of B. rubens was closer to that of C. introflexus than to P. formosum. The sensitivity of mosses exposed to asulam is discussed in relation to previous laboratory experiments.

The new species, Gyalectidium floridense Safranek & Lücking, found on leaves of Citrus in Florida, is described and illustrated. Gyalectidium floridense belongs in the G. areolatum group (Gyalectidium sect. Areolectidium ser. Areolate), which is chiefly characterized by a crystalline thallus where the calcium oxalate crystals aggregate to form large areoles on the thallus patches. Within this group, the new species is distinguished by rather narrow, folded, and horn-shaped hyphophores produced on the thallus surface.