Five new species of foliicolous lichens are described from the montane forest in the States of Oaxaca and Puebla of Mexico. All new taxa belong to the family Gomphillaceae (Ostropales): Gyalectidium nashii sp. nov., G. paolae sp. nov., G. rosae-emiliae sp. nov., Gyalideopsis applanata sp. nov. (also known from Costa Rica and Guyana), and Tricharia oaxacae sp. nov. In addition, pycnidia are described for Fellhanera naevia (Vain.) Lücking & Cáceres, and diahyphae for Tricharia subalbostrigosa Lücking.

Increasing awareness of the importance of bryophytes in ecosystems has heightened efforts to conserve rare bryophyte species. Understanding the factors that influence rarity in bryophytes thus becomes valuable in developing conservation strategies. In order to decipher these patterns of rarity in mosses, 141 sites were sampled from a variable landscape in the Okanogan Highlands of Washington State. We split the 209 moss species found into three frequency groups (rare, frequent, and common) based on occurrence information and compared these groups based on different attributes. Comparison of these species to known lists of the area shows that the dry interior of Washington is grossly understudied. Moss distribution patterns on a local scale reflect world distribution patterns and may be dictated by habitat availability. Rare species occur on fewer habitats and occur in habitats that are unique or restricted on the landscape. Further, they occur more often in restricted mesohabitats (e.g., streams, cliffs, fens) than they do in unrestricted mesohabitats (forested or non-forested uplands). Mesohabitats, thus, emerge as an appropriate level for a coarse filter approach to prioritizing conservation efforts for rare mosses by land managers.

To assess the effects of high temperature stress on membrane permeability in mosses, we studied Plagiomnium acutum (Lindb.) T. Kop. and Thuidium cymbifolium (Doz. & Molk.) Doz. & Molk. in May and June 2001, using changes in conductivity measurements of the medium. The relative membrane permeability increased with the treatment duration within the range of 40–60°C. The higher the temperature, the more quickly the relative permeability increased. Regression curves indicate that the relationship between the relative percent permeability and temperature are S-shaped and fit a logistic model. The 50% injury temperatures (IT₅₀) are 44.1 and 45.3°C, respectively.

In this paper we segregate specimens from the genus Sticta in the Great Smoky Mountains National Park into phenotypic groups corresponding to putative species using traditional taxonomic methods, paying particular attention to specimens from the S. weigelii s. l. group, then employ phylogenetic analyses and rigorous statistics to test the robustness of these species groups. In order to circumscribe putative species and to resolve the S. weigelii complex, morphological, chemical, and molecular characters from the nuclear ribosomal DNA sequences of the entire Internal Transcribed Spacer region are analyzed separately and simultaneously using maximum parsimony or maximum likelihood. In addition to the bootstrap method, Bayesian statistics with the Markov Chain Monte Carlo algorithm are used to estimate branch robustness on the resulting reconstructed trees. Five out of six analyses recover the same five monophyletic putative species from the genus Sticta, indicating the concordance of DNA-based and morphology-based species delimitation. The phylogenies show that lichens identified as S. weigelii represented S. beauvoisii and the two new species described here – S. carolinensis and S. fragilinata. Sticta weigelii s. s. does not occur in the park. Specimens from Oregon identified as S. weigelii belong to another unnamed Sticta taxon. The remaining two monophyletic groups represent two species well known from the park–S. fuliginosa and S. limbata. Characteristics of secondary compounds detected by Thin Layer Chromatography (TLC) and High Performance Liquid Chromatography (HPLC) in S. fragilinata thalli are provided. Detailed descriptions, including morphology and chemistry, are provided for four Sticta species found in the Smoky Mountains: S. beauvoisii, S. carolinensis, S. fragilinata and S. fuliginosa.

The lichenicolous fungi represent an important ecological group of species that form obligate associations with lichens. They have been studied seriously for over 200 years and the European species are especially well collected. However, collecting in other areas has been far less systematic and many new species await discovery. North American species are especially under-studied and this review is intended to stimulate the collection and study of these species. To encourage this study by lichenologists, we review the sorts of interactions formed by lichenicolous fungi with their lichen hosts, discuss various aspects of host specificity, virulence, chemical ecology, and evolution of lichenicolous fungi and provide a complete taxonomic listing of lichenicolous genera arranged as far as possible into natural groupings. In each section we suggest research topics in need of further study, and provide a listing of significant literature. We hope by calling attention to the largely unexplored biodiversity of lichenicolous fungi, investigators will take up the study of these fascinating organisms.

Six little known species in the Parmeliella mariana complex are accepted and described: P. cinerata (Zahlbr.) P. M. Jørg., comb. nov. (Hawaii, Sri Lanka); P. exornata (Zahlbr.) P. M. Jørg., comb. nov. (Borneo, Hawaii); P. flavida P. M. Jørg., sp. nov. (The Phillipines), P. fuscata P. M. Jørg, sp. nov. (India); P. imbricatula (Müll. Arg.) P. M. Jørg., comb. nov. (South America), and P. vainioi (Zahlbr.) P. M. Jørg., comb. nov. (Borneo, Java, The Philippines). Parmeliella flavida is the only known species in the family to contain xanthones. Likewise an isidiate taxon in the P. pannosa complex is accepted as a species and named: P. isidiopannosa P. M. Jørg., stat. & nom. nov. (Central and South America).

Lectotypes are explicitly designated for 43 taxa in the genus Fossombronia Raddi, with neotypes designated for F. mauritanica Trab. and F. pusilla var. β capitata Nees. One name, F. pumila Dumort, is regarded as an orthographic error not based upon a specimen and thus, cannot be typified. The entries are listed alphabetically, each with the correct author citation, place of publication, and the herbarium of deposit. In addition, supporting comments are given for most selections. Fossombronia caespitiformis De Not. ex Rabenh. var. multispira Schiffn. is elevated to the rank of subspecies. Images of all type specimen labels may be viewed at:  http://bryophytes.plant.siu.edu/fossombronia.html

Bacidia iberica, a new epiphytic species, is described from central and southern Spain. It is closely related to Bacidia rubella (Hoffm.) A. Massal. The most important differences are in thallus morphology. Bacidia iberica has a squamulose thallus and whitish to greenish gray ascending squamules, whereas B. rubella has a granular thallus. In addition, B. iberica has slightly paler apothecia than B. rubella. Spore length, width, and length/width ratio are significantly different for the two species.

This paper presents the results of a study of the C. squamosa group in North and Central America. The group as understood here includes C. squamosa, C. subsoluta, and two new species—C. parviloba and C. phyllidizans. This group is common and variable, and C. squamosa and C. subsoluta have been described several times. Several new synonyms are given and lectotypes are selected for C. irrubescens and C. squamosa. Color photographs and distribution maps are presented along with a discussion of the variability. The most constant features are the subsquamulose thallus and the paraplectenchymatous layer below the hypothecium and in the upper proper margin.

The genus Menegazzia comprises five species in Taiwan, three of which are newly described: M. anteforata, M. primaria, and M. pseudocyphellata. All new species have the stictic acid complex chemistry, two-spored asci, bifusiform conidia, and lack soredia and isidia. They differ in medullary hyphae color, perforation shape and size, and apothecium margin ornamentation, as well as by gross morphology of the thallus and lobe configuration.

The Australasian lichen species Ramalea cochleata Müll. Arg. is placed into the new genus Notocladonia S. Hammer as Notocladonia cochleata (Müll. Arg.) S. Hammer. It is joined by a previously undescribed species from Australasia, N. undulata S. Hammer, a closed-axil, squamulose species with undulating apothecial tissue. Both species contain divaricatic and usnic acids. The Australasian species of Notocladonia are distinguished from species in the neotropical genus Ramalea Nyl. s. str. on the basis of their gross morphology, which is characterized by apically-borne apothecial tissue. In contrast, the species of Ramalea bear vegetative podetial tissue that grows above the apothecium. The lectotype for Ramalea tribulosa Nyl., the type species of the genus, is designated here.