A new species of Synarthonia, S. leproidica, is described from Luxembourg. Phylogenetic analyses of mtSSU and RPB2 sequences were used to determine the generic affiliation of this sterile species. Synarthonia leproidica differs from all other species of the genus by the combination of a leproid thallus and the production of psoromic acid. It is the sister species to S. muriformis in our phylogenetic analyses. The discovery of the new species suggests that other strictly sorediate lichen species might have been overlooked in Europe, even in intensely explored countries such as Luxembourg. Phylogenetic analyses further confirm the placement of Reichlingia anombrophila in the genus Reichlingia and of Synarthonia astroidestera in the genus Synarthonia. Arthonia atlantica is transferred to the genus Reichlingia as R. dendritica.

Porina collina Orange, Palice & Klepsland is described as new from siliceous rocks in the Czech Republic, Great Britain and Norway. The thallus produces isidioid propagules which resemble those in P. rosei, P. hibernica and P. pseudohibernica, but which are more fragile and poorly-defined, and almost ecorticate; the perithecial wall is dark purplish brown and the ascospores are 3-septate. Sequences of the mitochondrial ribosomal DNA suggest that the new species belongs in the Porina byssophila clade.

Two Tasmanian species of the genus Cresponea are treated: C. graemeannae Kantvilas sp. nov., characterized by a very thin, saxicolous thallus, apothecia with a thick, radially fissured margin, thinly pruinose disc, hypothecium inspersed with oil droplets, and 5–9-septate ascospores, 25–40 × 6–8 μm; and C. subpremnea (Kantvilas & Vĕzda) Kantvilas comb. nov. The latter has ascospores 30–58 × 4.5–7 μm, which distinguish it from the related C. plurilocularis (Nyl.) Egea & Torrente (ascospores 27–45 × 6–8 μm). The taxa are illustrated, discussed and compared. Cresponea litoralis Elix, based on an Australian type, is considered a synonym of Bactrospora myriadea (Fée) Egea & Torrente. A key to the species of Cresponea reported from Australia is presented.

Saxicolous, lecideoid lichenized fungi have a cosmopolitan distribution but, being mostly cold adapted, are especially abundant in polar and high-mountain regions. To date, little is known of their origin or the extent of their trans-equatorial dispersal. Several mycobiont genera and species are thought to be restricted to either the Northern or the Southern Hemisphere, whereas others are thought to be widely distributed and occur in both hemispheres. However, these assumptions often rely on morphological analyses and lack supporting molecular genetic data. Also unknown is the extent of regional differentiation in the southern polar regions. An extensive set of lecideoid lichens (185 samples) was collected along a latitudinal gradient at the southern end of South America. Subantarctic climate conditions were maintained by increasing the elevation of the collecting sites with decreasing latitude. The investigated specimens were placed in a global context by including Antarctic and cosmopolitan sequences from other studies. For each symbiont three markers were used to identify intraspecific variation (mycobiont: ITS, mtSSU, RPB1; photobiont: ITS, psbJ-L, COX2). For the mycobiont, the saxicolous genera Lecidea, Porpidia, Poeltidea and Lecidella were phylogenetically re-evaluated, along with their photobionts Asterochloris and Trebouxia. For several globally distributed species groups, the results show geographically highly differentiated subclades, classified as operational taxonomical units (OTUs), which were assigned to the different regions of southern South America (sSA). Furthermore, several small endemic and well-supported clades apparently restricted to sSA were detected at the species level for both symbionts.

The principal goal of our study was to test whether ecologically and chemically different populations of lichens in the Physconia muscigena group belong to a single, or multiple, species. We used sequence data from three markers (ITS rDNA, mtSSU rDNA and TEF1-α) for the reconstruction of phylogenetic trees based on a sampling of mostly European and Canadian populations of P. muscigena (Ach.) Poelt, P. muscigena var. bayeri (Nádv.) Poelt and P. isidiomuscigena Essl. In addition, we sought any possible geographical or ecological trends among chemotypes and haplotypes. Results show that: 1) sequence data of ITS rDNA and TEF1-α show large genetic variation in the Physconia muscigena group, which does not correlate with geographical distribution or thallus chemistry; 2) Physconia muscigena var. bayeri and P. isidiomuscigena appear undifferentiated with P. muscigena in our phylogenetic trees, and the three species cannot be distinguished on the basis of ITS rDNA, mtSSU rDNA and TEF1-α sequences. We therefore synonymized Physconia muscigena var. bayeri with P. muscigena and we recombine P. isidiomuscigena as a variety of P. muscigena.

Fruticose lichens of the genus Usnea Dill. ex Adans. (Parmeliaceae), generally known as beard lichens, are among the most iconic epiphytic lichens in modern forest ecosystems. Many of the c. 350 currently recognized species are widely distributed and have been used as bioindicators in air pollution studies. Here we demonstrate that usneoid lichens were present in the Palaeogene amber forests of Europe. Based on general morphology and annular cortical fragmentation, one fossil from Baltic amber can be assigned to the extant genus Usnea. The unique type of cortical cracking indirectly demonstrates the presence of a central cord that keeps the branch intact even when its cortex is split into vertebrae-like segments. This evolutionary innovation has remained unchanged since the Palaeogene, contributing to the considerable ecological flexibility that allows Usnea species to flourish in a wide variety of ecosystems and climate regimes. The fossil sets the minimum age for Usnea to 34 million years (late Eocene). While the other similar fossils from Baltic and Bitterfeld ambers cannot be definitely assigned to the same genus, they underline the diversity of pendant lichens in Palaeogene amber forests.