The moss Tortula ruralis is an important experimental system for studying the molecular and biochemical mechanisms of vegetative desiccation tolerance in plants. EST searches have identified a cDNA Aldh7B6 encoding a turgor-responsive aldehyde dehydrogenase (ALDH7). ALDH7B6, the 516 amino acid deduced polypeptide, is more than 60% identical to homologues from the protein family ALDH7. ALDH7B6 has a predicted molecular mass of 55.1 kDa and predicted pI of 5.87. RNA blot hybridizations were used to analyze expression of Aldh7B6 in response to desiccation, NaCl, altered light levels, ABA, & UV-C. Aldh7B6 steady-state mRNA transcript levels are unchanged in response to all treatments and the gene is constitutively expressed. We propose three conserved signature sequences for ALDH7 protein members: 1) the PR-box PAPKRGEIVRQIGD (residues 83–96), 2) the catalytic box FAAVGTAGQRCTT (residues 297–309), and the C-box (residues 424–515 of the carboxy terminus). We postulate that ALDH7B6 plays an important role in the detoxification of aldehydes generated in response to desiccation-stress and propose that ALDH7 homologues are more properly described as “stress aldehyde” ALDHs.

Forest floor termite structures in Amazonia are attractive substrates for certain taxa of Fissidens (Bryophyta), four of which appear to grow preferentially on termite structures. A degree of adaptive co-evolution is suggested for the taxa which prefer the termite nest substrate because the termite structures provide an organically enriched naked soil-like substrate for the Fissidens, elevated above the forest floor leaf litter. Also, the protective overlapping growth pattern of the Fissidens plants may function to abate rain fall erosion of the termite structures. Fissidens, with 18 taxa collected from Amazonian termite structures, is by far the most important bryophyte exploiting this habitat; only a few other mosses and a few hepatics have been collected—irregularly—from the termite structure substrate.

According to phylogenetic analyses of nrDNA ITS1 and ITS2 sequences (including the 5.8S unit) the Neotropical Plagiochila moritziana, P. rutilans var. rutilans, P. rutilans var. standleyi, P. trichostoma (= P. permista, syn. nov.), and P. subtrinitensis form a monophyletic lineage and are placed in P. sect. Rutilantes; all five taxa lack a ca 20 base pair sequence that is present in all the taxa of the other Plagiochila sections investigated. The Central American P. subtrinitensis is treated as a synonym of the Hawaiian endemic P. deflexa. Plagiochila moritziana is excluded from sect. Fuscoluteae and reduced to a variety of P. rutilans; P. sect. Permistae is treated as a synonym of P. sect. Rutilantes. The sporophytes of P. trichostoma and P. deflexa are described for the first time. Fresh material of P. rutilans var. moritziana exhibits a distinct odor of peppermint caused by the presence of several menthane monoterpenoids, principally pulegone. The Central American P. rutilans var. standleyi is reported from Ecuador, new to South America. Lectotypes are designated for P. rutilans var. moritziana, P. subtrinitensis, and P. trichostoma.

Phenology is interpreted as the study of the timing of growth and reproductive events, and it underpins a great proportion of the field of reproductive ecology. Salient early works in bryophyte phenology provided broad-based compilations of important phenological characteristics for entire local bryofloras in Germany and European regions, including branching architecture, the timing of vegetative growth, gametangial initiation times, fertilization times, the duration of sporophyte development, and the time of spore liberation. Recent work in the field was incited by the formulation of a phenological classification system for mosses proposed by Stanley Greene and placed into context by Royce Longton. Phenology in the broad sense is seen to intersect the fields of stem architecture, growth rates, nutritional status, structural development, population dynamics, fertilization biology, fitness measures, the interplay between sexual and asexual reproduction, spore dispersal patterns, sex dimorphism, clinal variation, and desiccation tolerance, among others. The principal patterns of gametangial and sporophytic maturation are reviewed, and a “consensus system” for presenting phenological data is presented that combines the categories of maturation postulated by Greene, the functionality stressed by Forman, and the numerical basis refined by Longton. The field of phenology has a bright future inasmuch as the research continues to focus on individual species and seeks to branch out into the fertile disciplines of sex expression, sex ratios, and resource distribution. The most useful tool for the bryophyte phenologist in investigations of these disciplines may very well rest with allocational bryology.

Three species are placed in the lichen genus Rimularia Nyl.: R. michoacanensis (B. de Lesd.) comb. nov., R. paradoxa Timdal & W. A. Weber sp. nov., and R. subconcava (H. Magn.) comb. nov. The species differ from the previously recognized species of the genus in having squamulose thalli and filiform pycnoconidia. Rimularia michoacanensis is a terricolous species from central Mexico, R. paradoxa a saxicolous species from Colorado, U.S.A., and R. subconcava a terricolous species from central Asia (China and Kirgiziya).

The breeding system of Fossombronia foveolata and genetic differentiation in the F. foveolata species complex were studied using Random Amplified Polymorphic DNA (RAPD) markers. Polymorphism values for cloned siblings were not significantly different from those obtained from amplification of identical DNA samples. These results support the hypothesis that sporophytes display high levels of homozygosity. Nevertheless, low levels of genetic differentiation were detected between F. foveolata populations from spatially separated sites in southern Illinois. Monomorphism among siblings, low levels of polymorphism among southern Illinois populations, sporophyte production in clonal cultures maintained in an environmental chamber, growth of cultured clonal mats to sizes comparable to field populations, and short sperm and spore dispersal distances suggest that F. foveolata populations are probably established from single founder events and are maintained through inbreeding and vegetative reproduction. Degree of genetic relatedness among F. foveolata from Illinois, F. foveolata from Texas, F. cristula from Indiana, F. japonica from Japan, F. lamellata from Arkansas, F. porphyrorhiza from Brazil, F. pusilla from California, and F. texana from Texas were also estimated from RAPD data. UPGMA cluster analyses of several different similarity matrices resolved the following three species groups 1) F. foveolata, F. lamellata, F. cristula group; 2) F. japonica, F. porphyrorhiza, F. pusilla group; and 3) F. texana. These groupings are consistent with those based on analyses of morphological characters, as well as other molecular data sets.

The sensitive lichen Usnea longissima Ach. has a limited, patchy distribution across forested landscapes in the U.S. Pacific Northwest. To gain insight into whether the current distribution within the Oregon Coast Range has resulted from a lack of suitable habitat or from dispersal limitations, we measured growth of U. longissima transplants placed in four habitats. Transplant study site locations and habitats were determined through an accompanying study that identified significant U. longissima habitat characteristics, based on the present distribution of the species, and used predictive modeling to identify areas of apparently suitable habitat within the study area. Transplants were placed in 12 sites, comprised of three replicates of the four habitats. Ninety transplants were placed in each habitat (n = 360). Growth was measured as changes in biomass and length after one year. Transplants grew in all habitats, particularly in sites where habitat was predicted to be least suitable for U. longissima. Although transplants in those sites had mean biomass increases that were 2.7 to 4.6 times greater than those of transplants placed in the other three habitats, their overall rate of attrition was 1.5 to 1.8 times higher than transplants in the other three habitats. Increases in length were also greatest in sites where habitat was predicted to be least suitable. The fact that the transplants grew well in all habitats and actually thrived in sites where habitat was predicted to be least suitable indicates that dispersal limitations may play a more significant role than the availability of suitable habitat in determining the distribution of U. longissima in the Oregon Coast Range. These findings underscore the importance of green tree retention during timber harvests. Trees containing U. longissima should be retained so that they may inoculate the regenerating stand with U. longissima fragments. It is also recommended that stands harboring significant populations of U. longissima (typically old stands) be preserved as source locations of this dispersal-limited species.

Fissidens philonotulus Besch., known from the Society Islands and Fiji, is considered to be the same as the widespread and variable F. ceylonensis Dozy & Molk. Fissidens pascuanus Broth., an endemic on Easter Island, is considered to be closely related to F. linearis var. obscurirete (Broth. & Paris) Stone. A lectotoype of F. pascuanus is designated.

Seedling establishment on iron mine tailings in New York State's Adirondack Park was studied to determine if cover by the bryophyte Polytrichum piliferum Hedw. facilitated or inhibited seed germination and seedling survival, relative to other substrates present on the site. The occurrence of vascular vegetation on the four most commonly occurring substrates (bare tailings, cryptogamic crust, grass litter, and Polytrichum piliferum) was compared. An association survey detected preferential association between vascular vegetation and cover of Polytrichum piliferum, particularly for winter annual and biennial species. Seeds of Panicum virgatum L. and Melilotus officinalis (L.) Pallas were experimentally sown onto the four natural substrates, as well as on artificial substrates designed to mimic bryophyte turf. Germination on Polytrichum turf exceeded that of other substrates. However, seedling survivorship was low on all substrates, with no seedling surviving past 13 wk. Shade treatment on natural substrates significantly increased germination and somewhat extended survival. The results suggest that Polytrichum cover acts as a safe site for species that germinate and establish in cooler weather. However, even experimental shading of moss turf does not ameliorate summer heat stress sufficiently to permit establishment of seeds that germinate in early summer.

Pseudephemerum is newly reported from Oregon, U.S.A. and Tlaxcala, Mexico. With examination of available specimens including types, Pleuridium tenellum is proposed as a new synonym of Pseudephemerum nitidum.

Two widespread, polymorphic, but morphologically similar species of Pleuridium have long confused botanists. The sexual condition (autoicous versus paroicous) and perichaetial leaf lamina thickness (unistratose versus bistratose) morphologically distinguish Pleuridium subulatum from P. acuminatum. Additional evidence from cytological voucher specimens revealed that two chromosome numbers (n = 13 and n = 26) are congruent with the two respective taxa. Pleuridium subulatum (Hedw.) Rabenh. is lectotypified by a specimen from the herbarium of J. Hedwig and Pleuridium acuminatum Lindb. by a specimen from the herbarium of S. O. Lindberg).

Grimmia teretinervis is thought to occur sporadically across the North American continent. New site records from Alberta, the Yukon Territory, and Alaska are linked to the margin of the Cretaceous epicontinental seaway. Geological maps from other areas of the continent reveal that G. teretinervis is associated with deposits from other ancient epicontinental seaways. All areas have experienced either faulting or fluvial erosion that have exposed massive sections of calcareous sediments that are suitable microhabitats for G. teretinervis.

A new species in the formerly monotypic genus Vitalianthus is described from Amazonas State, Brazil. Vitalianthus urubuensis sp. n. exhibits leaves with an unbroken chain of ocelli, upright orientation of the underleaf lobes, and a 4-keeled perianth lacking horn-like projections; all features that distinguish the only other known member of this genus, V. bischleriana (Porto & Grolle) R. M. Schust. & Giancotti. Differences between V. urubuensis and V. bischleriana are most evident in leaf and lobule morphology. The discovery of this new species in central Amazonia dramatically expands the geographic range of Vitalianthus, a taxon once considered endemic to the coastal rainforests of northeastern Brazil.

Pyxine subcinerea Stirton is newly reported for New York State. The distribution of Pyxine subcinerea in the eastern United States is established. Morphological and chemical differences between P. subcinerea, P. albovirens, and P. caesiopruinosa are recognized, clarified, and expanded upon.

In November 1999, during a field trip along the eastern slopes of the Californian Sierra Nevada, at five different localities a Grimmia species was found that, with some doubt, was identified as Grimmia mariniana Sayre. Recent comparison with fresh material of this species, and with the type specimen, revealed that the Sierra Nevada plants differ in sporophytic as well as in gametophytic characters. As a result of this, it is described and illustrated as Grimmia nevadense H. C. Greven, spec. nov.