Usnea viktoriana P. Clerc & Otte is described as new. It is characterized by the presence of alectorialic acid as major secondary compound mainly present in the aggregated efflorescent soralia with long isidiofibrils. Usnea parafloridana K. Mark, Will-Wolf & Randlane is synonymized with U. praetervisa (Asahina) P. Clerc. Both U. viktoriana and U. praetervisa are supported by molecular analysis. A key to the shrubby-subpendulous sorediate Usnea species in Europe is provided.

Recently, nine species of lichenicolous fungi were found growing on Cetraria aculeata (Parmeliaceae) in a sand dune system in the Ukraine. One of them, Didymocyrtis trassii, is described here as new to science. This species is similar to D. pseudeverniae but differs in having smaller pycnidia, smaller obpyriform to clavate conidia as well as its DNA sequence. The new monotypic lichenicolous genus Katherinomyces is described here. Acremonium lichenicola s. l., Eonema pyriforme, Didymocyrtis cladoniicola and Lichenoconium erodens are reported for the first time on Cetraria aculeata. Furthermore, E. pyriforme is reported for the first time from lichen thalli. Acremonium lichenicola, E. pyriforme and Taeniolella rolfii are new for the mycobiota of the Ukraine. A key to the eleven known lichenicolous species on Cetraria aculeata is provided.

The new species Ramalina fleigiae from Brazil is described growing on rocks in riverbeds in high altitude grasslands of southern Brazil. It grows in areas with constant water flow, sometimes almost immersed, and always in exposed habitats. Through an integrative approach, the detailed description of R. fleigiae includes morphological, anatomical, ecological, chemical and molecular data. Ribosomal DNA-based phylogenies suggest that R. fleigiae is more closely related to a species that shares its habitat preference (R. laevigata) than to the morphologically and chemically similar R. exiguella and R. gracilis. Ramalina fleigiae and R. laevigata can be distinguished by thallus morphology (irregularly flat branches in R. fleigiae vs. flat to canaliculate in R. laevigata) and pattern of chondroid tissue, as genetic distances between them are compatible with the interspecific range. It is possible that many species of Ramalina still remain hidden within the morphological or chemical variation of currently accepted species. Combining ecological, anatomical and molecular data will improve our future understanding of this genus.

Maintenance of biodiversity in managed forested landscapes requires detailed knowledge of the ecological requirements of specialist organisms linked to key microhabitats. Here we examine the relationship of 37 lichenized and unlichenized epiphytic calicioid species to stand age and substratum type in seven pairs of mid-seral (70–165 y) and old (220–470 y) forest stands in humid east-central British Columbia. Based on our inventory of eight host tree species, total calicioid diversity and mean species richness are highest in old stands, with 12 species not detected and nine additional species much less frequent in mid-seral stands. Thuja plicata supports by far the highest level of total calicioid diversity, with 31 of 37 species; mostly associated with very old trees. Owing primarily to the late recruitment of lignicolous calicioids, stand-level calicioid richness continues to increase into the 5th century after stand initiation. Our study thus has two major findings pertinent to the maintenance of forest biodiversity in managed forests: first, stand-level calicioid richness increases slightly for at least three centuries past the acquisition of old-growth status; second, remnant trees and snags carried forward into mid-seral, regenerating stands enhance overall calicioid species richness. These results suggest that very old old-growth (= ‘antique’) forests might play an important role in the long-term maintenance of calicioid species richness, further suggesting that the standard practice of lumping all forests above a set age into a single old-growth category is not ecologically tenable for all taxonomic groups.

The genus Coenogonium Ehrenb. in Tasmania comprises seven species. New to science are: C. atherospermatis Kantvilas, Rivas Plata & Lücking, endemic to Tasmania and characterized by pale yellowish beige apothecia and relatively small ascospores, 6–8·5×2·5–3 µm; C. urceolatum Kantvilas, Rivas Plata & Lücking, likewise endemic to Tasmania and characterized by orange, urceolate apothecia, 0·3–0·4 mm wide, and uniseriate ascospores, 8·5–11×2·5–3 µm; and C. australiense Kantvilas & Lücking, recorded from Tasmania, South Australia and New South Wales, and characterized by orange apothecia, 0·5–2 mm wide, and relatively broad ascospores, 10–14×3–4·5 µm. Also treated are C. lutescens (Vĕzda & Malcolm) Malcolm (Tasmania and New Zealand) and three widespread taxa, namely C. implexum Nyl. (Southern Hemisphere), C. luteum (Dicks.) Kalb & Lücking and C. pineti (Schrad. ex Ach.) Lücking & Lumbsch (both subcosmopolitan). All species are described in full from Tasmanian collections and illustrated, and their ecology, variation and affinities to related species are discussed. The Tasmanian taxa are also discussed in the context of the Australasian lichen biota.

How growth is distributed within the morphologically diverse thalli of lichens is still poorly known and the anatomical mechanisms involved are not well understood. This work applies electron microscopy (SEM and TEM) to examine cell- and tissue-level events in the umbilicate thallus of Lasallia pustulata, whose pattern of expansion was the subject of a previous field study. Stacks of epinecral tissue accumulating at the thallus surface showed broadening bases and recurring rupture attributable to diffuse expansion of the living tissue below. Cortical cells, dividing anticlinally, adjoined septa to previous septa, indicating parenchymatous divisions. These observations are all consistent with previous contentions that mature, organized tissues within the thallus are capable of continued diffuse growth. They provide a developmental explanation for the morphology of the epinecral layer and suggest that anatomical characteristics may be helpful in recognizing diffuse growth patterns. Parenchymatous cell divisions, believed until recently to never occur in lichen thallus tissues, are shown to play a developmental role in the diffuse growth of the umbilicate lichen thallus.