Caloplaca gyalectoides S. Kondratyuk & Kärnefelt from the Cape Province, South Africa, and Caloplaca chilensis S. Kondratyuk, Kärnefelt, Frödén & Arup with an associated parasymbiont Arthonia tetraspora S. Kondratyuk & Kärnefelt occurring mainly along the coast in central Chile are described as new. Possible associated taxa are briefly discussed. Distribution maps are provided for all three species.

The circumscription of the Plagiotheciaceae was evaluated cladistically, using anatomical and morphological data, plus rps4 and trnL-trnF gene sequences. Two analyses were conducted with 37 ingroup species, representing 14 genera, and eight outgroup species. First, the rps4 (73 informative nucleotide sites) plus trnL-trnF data set (39 sites) was analyzed alone. This initial analysis suggests a highly polyphyletic Plagiotheciaceae, with Acrocladium, Catagonium, Herzogiella, Isopterygiopsis pulchella (Hedw.) Iwats., Isopterygium, Plagiothecium piliferum (Sw.) Schimp., Pseudotaxiphyllum elegans (Brid.) Iwats., P. pohliaecarpum (Sull. & Lesq.) Iwats., Rhizofabronia, Struckia, and Taxiphyllum placed among the outgroup taxa. In a second analysis, the rps4 trnL-trnF data set was combined with anatomical and morphological data (adding 53 informative characters). The results of the latter analysis are congruent with the first analysis regarding Herzogiella adscendens (Lindb.) Iwats., Isopterygium, and Taxiphyllum, but resolves the rest of the Plagiotheciaceae as a monophyletic group. The results suggest that the following genera belong to the family: Acrocladium, Bardunovia, Catagonium, Herzogiella, Isopterygiopsis, Orthothecium, Myurella, Plagiothecium, Platydictya, Pseudotaxiphyllum, Rhizofabronia, and Struckia. DNA sequence, morphological, and anatomical data are all important when evaluating the circumscription and internal relationships of the family. We suggest that especially the relationships among Plagiothecium, Pseudotaxiphyllum, and Struckia species can be better resolved by additional molecular evidence. The ancestor of the Plagiotheciaceae was most likely a southern temperate species, whereas most of the later diversification within the family occurred in the northern temperate zone. Only one genus, Rhizofabronia, evolved in tropical mountains, whereas scattered members of other genera occur in similar environments. Adaptations for calcareous substrates evolved either in the ancestor of the entire Isopterygiopsis-Plagiothecium clade and were lost twice, or they evolved independently in Isopterygiopsis and in a clade consisting of Bardunovia, Myurella, Orthothecium, and Platydictya.

The nomenclatural consequences of a phylogenetic study of the Plagiotheciaceae are presented. Bardunovia Ignatov & Ochyra is synonymized with Platydictya Berk. The species that was called Herzogiella adscendens (Lindb.) Z. Iwats. & W. B. Schofield (Stereodon adscendens Lindb., Campylium adscendens (Lindb.) Mitt.) in the recent literature is transferred to Hypnum Hedw., as H. adscendens (Lindb.) Jaeg. An understanding of the exact relationships of the latter will have to await a generic revision of Hypnum.

A set of 700 moss specimens from the Montes Azules Biosphere Reserve accounts for a list of 136 species and varieties, including ten species new to Mexico, for the Lacandon Forest of eastern Chiapas. With the addition of eight published reports, a total of 144 taxa are now recorded from major habitats in this area. The Caribbean relationships in this moss flora, with 82 species, are the most important while endemic taxa are virtually absent. Although the neotropical character of the Lacandon Forest moss flora is further emphasized by eleven Meso-American species, the widely distributed groups are also represented; 31 pantropical and 14 disjunct taxa are shared with other tropical areas. The patterns of distribution, the life-forms, and the structural diversity of mosses are features that should be preserved in eastern Chiapas in order to maintain biological attributes that have been eliminated from other tropical areas in Mexico.

Upper montane oak forests in the Cordillera de Talamanca show a high diversity of bryophyte species and great diversification of microhabitats. A complete bryophyte inventory of six hectare of forest yielded 206 species: 100 mosses, 105 hepatics, and one hornwort. Based on similarities in species composition the forest microhabitats cluster into three main groups: 1) forest floor habitats (including tree base), 2) phyllosphere, and 3) other epiphytic habitats. The contribution of forest floor habitats to total bryophyte species richness is much higher than in forests of lower elevational belts. Distribution of species and life forms in different microhabitats reflect the vertical variation of humidity and light regimes. At the same time they show the impact of the pronounced dry season and the structural characters (tree height, stratification, number of host tree species) of these oak forests on epiphytic bryophytes compared to more humid forests and upper montane forests of lower stature.

The peristome of O. obtusifolium Brid. is typically double and composed of remnants of cell walls from three peristomial layers. A prostome has never been reported for this species. Here we report the occurrence of a prostome for this taxon based on a single population from western Canada. This prostome extends over the complete surface of the exostome tooth, but falls off shortly after the dehiscence of the capsule.

Chaenotheca nitidula is described as a new species from northeastern North America. It is characterized by long, shining stalks; rather small, spheric, non-pruinose capitul; immersed thallus; and its association with Stichococcus as photobiont. In a phylogenetic analysis based on rDNA ITS1–5.8S-ITS2 sequences, C. nitidula was most closely related to Chaenotheca gracilenta and C. gracillima. It occurs on wood of conifers in old woodlands and has so far been recorded from Maine and New Brunswick.

Leptogium cellulosum and L. teretiusculum are much more frequent and widespread in the Pacific Northwest of North America than previously recognized. Leptogium cellulosum, formerly known from only a few sites, is now known from over 50 sites in the Pacific Northwest. We describe habitat and associated macrolichen and crustose lichen communities for these species. In addition, we examined morphological variation of L. cellulosum in the Pacific Northwest. Three widespread morphological variants of L. cellulosum occurred at similar percentages of plots sampled in northern Idaho. Leptogium teretiusculum is relatively constant in morphology, however it must be carefully distinguished from the terete morph of L. cellulosum.

Plant material from the Canary Islands similar to Plagiochila spinulosa (Dicks.) Dumort. has been identified as the Neotropical liverwort P. stricta Lindenb. The secondary metabolite profiles of CDCl₃ extracts of both Neotropical and Macaronesian specimens of P. stricta are distinct from those of P. spinulosa in containing alloocimene and neoalloocimene as the principal monoterpenes rather than β-phellandrene; the two species also show differences in the 9,10-dihydrophenanthrenes and other aromatic compounds present. Phylogenetic analyses of ITS nrDNA sequence variation place P. spinulosa sister to P. stricta. Morphologically, P. stricta from Tenerife is distinguished most easily from P. spinulosa by the scarcely decurrent antical leaf margin.

Phylogenetic analyses of infraspecific molecular data in relation to geographic and ecological information has come to be known as phylogeography. Bryophytes offer fertile material for such analyses, which can help clarify long standing biogeographic questions that were intractable before molecular data became available. In particular, molecular data can help distinguish between dispersal and fragmentation explanations for disjunct distributions that characterize many bryophytes at the specific as well as higher levels. Phylodemography is the application of molecular data and phylogenetic analyses to infer past changes in population size within species. Grounded in coalescence theory from population genetics, this new field could be fruitfully applied to bryophytes. Combining phylogeography and phylodemography yields a powerful strategy for elucidating evolutionary processes.

We investigated biomass allocation patterns in sporophyte-bearing and non-sporophytic plants of the perennial moss Dicranum polysetum Sw. from southern Sweden by comparing dry masses of various reproductive and vegetative plant modules. Assessing parental vegetative biomass is critical in bryophytes due to continuous decay of basal shoot portions. We propose a method to estimate the photosynthetically active gametophyte biomass at the onset of the current sporophyte cycle retrospectively. With this measure for vegetative plant size, the proportional investment in reproductive structures, reproductive effort, was 16% when sporophytes were produced, and 1.3% when perichaetia remained unfertilized. In sporophytic plants, vegetative apical growth and reproductive output (measured both as dry mass and sporophyte number) were positively correlated, and reproductive effort was inversely related to the mass of the annual segment preceding sporophyte initiation. The development of mature sporophytes was negatively associated with annual shoot segment and innovation size. Moreover, sporophyte development reduced the probability of future perichaetial initiation and the mass of new perichaetia. In sporophytic individuals, investments in innovations and reproductive structures were negatively correlated. Mean mass per sporophyte perichaetium decreased with increasing number of mature sporophytes per perichaetium. These patterns strongly suggest that D. polysetum experiences a cost of sexual reproduction, that sporophyte maturation is resource limited, and that apical sinks compete.

The pyrenocarpous lichen Henrica americana is described as new. It is the second known species of the genus that is related to Polyblastia. The new species is characterized by small, brown, umbilicate squamules on a black hypothallus; black, double-walled perithecia perched on the squamules or on the stipes; and brown muriform ascospores. It is known only from a single locality in Montana.

Nomenclatural problems in the liverwort Petalophyllum are addressed. Following a review of the original description of the genus, it is concluded that Petalophyllum Nees & Gottsche ex Lehm. or simply Petalophyllum Lehm. is the correct citation for the genus. The correct citations for the two species intially placed in the genus are P. preissii Lehm. and P. ralfsii (Wilson) Nees & Gottsche ex Lehm. and a designation of P. preissii as the type species for the genus is accepted. Lectotypes are designated for P. preissii, P. ralfsii, P. bolivianum Steph., P. indicum Kashyap, and Fossombronia corbulaeformis Trab. and a neotype is designated for P. lamellatum (Nees) Lindb. Petalophyllum australe Colenso and P. macrocalyx Colenso have been proposed for rejection since there are no extant specimens of these taxa and their protologues are beset with interpretive problems.

The gravitropic response of Pellia epiphylla (L.) Corda sporophytes was analyzed using digitized images from infrared video recordings. Lateral transport of radioactively labeled auxin was followed using agar block and liquid scintillation techniques. Upward gravitropic curvature of horizontally oriented sporophytes was detected within 50 to 60 minutes. Growth rates on the top sides of sporophyte setae dropped from 0.53 to 0.29 mm hr⁻¹, and rose on the bottom from 0.53 to 0.88 mmAhr⁻¹. ¹⁴C-labeled indoleacetic acid (IAA) applied in donor blocks moved preferentially toward the lower side of setae in horizontally oriented sporophytes, with three-fold polarity established after 40 minutes. Negligible movement of label from blocks was detected in setae of vertically positioned controls tested after the same interval. These observations are consistent with a mechanism for gravitropism in Pellia that involves lateral redistribution of IAA.

The new genus Kachbrenneriella Diederich & M. S. Christ. is described to accommodate the lichenicolous hyphomycete Torula cyanescens Kalchbr., and the new combination K. cyanescens (Kalchbr.) Diederich & M. S. Christ. is proposed. As the type specimen is considered to be lost, a neotype is designated. The fungus forms a whitish tomentum on Usnea thalli, composed of erect conidiophores on which hyaline, catenate conidia develop, and is known from Europe, Canada, and Papua New Guinea.

Growth form and substrate influences on elemental accumulation patterns were investigated in four lichen species. Two fruticose species (Usnea amblyoclada on rock and Usnea hirta on bark) and two foliose species (Flavoparmelia caperata on rock and Flavopunctelia flaventior on bark) were collected below Massai Point in Chiricahua National Monument in southeastern Arizona, U.S.A. Samples were analyzed for 14 elements. A two-way ANOVA model was used to examine the relationships between substrate and growth form (independent variables) on element accumulation (dependent variable) patterns in lichen samples. In the ANOVA model the growth form variable was significant for K, Ca, Ti, Ba, Fe, Ni Cu, Zn, Pb, Rb, and Sr while the substrate variable was significant for K, Ti, Mn, Fe, Ni, Rb, and Sr. A significant interaction between the two class variables was observed for P, K, Ti, Mn, Fe Ni, Rb, and Sr. Accumulation of sulfur appeared to be independent of both growth form and substrate influences. In this study growth form was a key factor affecting element accumulation patterns in lichens. It is proposed that thallus continuity and orientation, which partially define growth form characteristics, influenced the accumulation of elements from airborne and substrate sources.

Sphaerolejeunea umbilicata Herzog, the only species of the genus Sphaerolejeunea Herzog, was until now known only from the type material collected in the Andes of Colombia in 1922. This critically endangered epiphyllous liverwort was rediscovered recently in the understory of a lower montane rainforest in northern Peru. It stands out by its leaf lobes bordered by hyaline cells, strongly inflated lobules, and terete perianths without keels or beak. The sporophyte, described here for the first time, is characterized by the seta made up of 4 12 cells, valves remaining suberect after dehiscence, the inner tangential capsule walls lacking fenestrate, sheet-like thickenings, and the 18 marginal and 4 additional elaters lacking spiral bands. Based on morphological similarities, Sphaerolejeunea is considered to be closely related to Lejeunea. In the present paper a complete description with illustrations is presented as well as a discussion of the ecology of the species, the systematic position and generic affinity of Sphaerolejeunea within the Lejeuneaceae, and its conservation status.

Cololejeunea javanica (Steph.) Mizut. and C. mackeeana Tixier are proposed as synonyms of C. angustiflora (Steph.) Mizut. Cololejeunea flavicans (Steph.) Mizut., previously synonymous with C. javanica, is reinstated. The position of hyaline papilla in Cololejeunea ciliata Pócs is the same as that in C. angustiflora. Cololejeunea ciliata is distinguished from C. angustiflora primarily by the irregularly ciliate-dentate margin of the leaf.

We studied epiphytic macrolichen communities and occurrences of rare species along the transition from upland to riparian forests on a range of stream sizes (intermittent, non-fish-bearing perennial, fish-bearing but less than 5^th order, and streams larger than 5^th order), based on 92, 0.38 ha plots in the McKenzie River watershed of the central Cascades of Oregon. The transition from uplands higher in the watershed to riparian areas along large streams is expressed in decreasing elevation and increasing representation of hardwoods. Upland stands were almost 100% conifers, averaging 49 m²/ha in stand basal area, decreasing to 48% conifers along fish-bearing streams of fourth order and below, and finally to 30% along large streams. Stand basal areas of hardwoods averaged near zero in uplands, increasing to an average of 11 m²/ha along large streams. One NMS ordination axis described this gradient in macrolichen communities, expressing 72% of the variation in community composition. Epiphytic lichens along large streams differed from fish-bearing streams smaller than fifth order; both of these stream classes also differed strongly from each of the other stream classes. Epiphytic lichens in uplands, along intermittent streams, and non-fish-bearing streams overlapped broadly in species composition. Macrolichen species richness was highest along large streams, averaging 38 species per plot, versus about 28 species per plot for uplands and non-fish-bearing streams. This difference is attributable to more species of cyanolichens, matrix lichens, and nitrophilous lichens along the large streams. About half of the individual species differed in abundance among stream classes, based on Indicator Species Analysis. Listed species (considered at risk by a government agency) were 57% more frequent in riparian areas along large streams than in uplands or along small streams. Protecting riparian zones from logging and urbanization and other forms of habitat destruction will, therefore, protect many rare species. Uplands and small streams, however, supported distinctive macrolichen communities, including rare species that were infrequent or absent from the riparian zones of large streams.

To compare effects of aspect, height on tree, and host species on species richness and cover of epiphytic lichens and bryophytes on conifers, we sampled Chamaecyparis nootkatensis, Picea sitchensis, and Tsuga heterophylla on the north and south sides in the first, second, and third meters of tree trunks in Vladimir J. Krajina Ecological Reserve. A total of 11 taxa of mosses, 26 of liverworts, and 4 of lichens were recognized. Bryophytes, especially liverworts, dominated in both cover and number of occurrences, with the most common being Dicranum scoparium, Isothecium myosuroides, Bazzania flaccida, and Scapania bolanderi. Rhytidiadelphus loreus was abundant at the tree bases but not at other heights. There was no host specificity. The rough mat growth form comprised both the highest cover and greatest number of species of bryophytes on each of the three tree species. This study demonstrates that under the right bark conditions liverworts can be more abundant than mosses and both more abundant than lichens on conifer bark.

Two remarkable, new species from the Arctic are added to the terricolous Fuscopannaria praetermissa complex: F. abscondita P. M. Jørg., with apothecia hidden among the claviform squamules, from Svalbard and F. viridescens P. M. Jørg. & Zhurb. the first example of a species with a green photobiont in this genus, from Siberia and Alaska.

Hypogymnia bryophila McCune is described as a new species of lichenized fungi from Portugal. Previously included under H. farinacea Zopf (syn. H. bitteriana (Zahlbr.) Räs) or H. austerodes (Nyl.) Räs., it often has terminal soralia similar to H. bitteri (Lynge) Ahti, as well as laminal soralia, but the soralia appear along edges of cracks in the cortex, similar to H. farinacea. Furthermore, the lobes are more lax and imbricate as compared to these other species. Hypogymnia bryophila is the only species of the 85 known in this genus that contains protocetraric acid without physodalic acid. A protocetraric acid-deficient chemotype is also known. So far H. bryophila is known primarily from mossy granitic rock, rarely on Pinus pinaster, in Serra da Estrela and Serra de S. Mamede, Portugal.

Forty-five lichen species are reported from Aldabra, an atoll of four main islands and numerous islets located in the Indian Ocean. Thirty-three species are new to Aldabra. The lichen flora is characteristic of the Indian Ocean islands. It is dominated by pantropical species, showing a rather weak statistical correlation (Sørensson Coefficient) of 22.0 between Aldabra and the islands of the granitic Seychelles and a surprisingly higher correlation of 36.5 with the Chagos Archipelago more than five times the distance away.