Leprocaulon calcicola is described as new from walls in SE England; it is leprose, pale to mid blue-grey, and contains zeorin and usnic acid. It differs from L. knudsenii from North America in its habitat on mortared walls rather than non-calcareous rock and in its ITS sequence. ‘Lecanora’ ecorticata differs in the yellower colour, and the presence of unidentified fatty acids and traces of unknown terpenoids (but not zeorin) by thin-layer chromatography. Leprose lichens with usnic acid are still poorly known and sequencing must be used to support morphological and chemical studies.

Macro-morphological features traditionally used to segregate genera in Parmeliaceae have been shown to be highly plastic, placing limits on their taxonomic value. Here we aim to elucidate the evolutionary relationships of the genera Relicina and Relicinopsis and reassess the phenotypic features traditionally used to separate these genera. To this end, we gathered ribosomal DNA sequences of ITS, nuLSU and mtSSU and analyzed them in a phylogenetic framework. Relicina was recovered as paraphyletic, with Relicinopsis nested within, and three different clades were identified within Relicina. Alternative hypothesis tests significantly rejected the monophyly of Relicina. Our results indicate that the presence or absence of bulbate cilia is of limited taxonomic value in this clade. Based on differences in conidia, however, we propose to accept Relicinopsis as a subgenus within Relicina as Relicina subgen. Relicinopsis (Elix & Verdon) Kirika, Divakar & Lumbsch. It is proposed that five new combinations of species previously classified in Relicinopsis be placed in Relicina.

Seventeen corticolous shrubby apotheciate Usnea species without vegetative propagules are reported from Brazil, including five species that are new to science: Usnea aurantiaca-parvula A. Gerlach & P. Clerc (characterized by an orange medulla and lageniform spinulose fibrils), U. cirrosa Motyka, U. cladocarpa Fée (syn. nov.: U. ramillosa Motyka), U. concinna Stirton (lectotype designated here, syn. nov. U. radiata Stirton, U. florida var. scabrosa Zahlbr.), U. cristatula Motyka, U. erinacea Vain., U. fleigiae A. Gerlach & P. Clerc (characterized by large spores and a thin, lax medulla), U. grandispora A. Gerlach & P. Clerc (characterized by large spores, a black base and protocetraric or salazinic acids in the medulla), U. kalbiana P. Clerc & A. Gerlach (characterized by a vitreous cortex and annular cracks in the basal part), U. lunaria Motyka, U. meridionalis Zahlbr. (syn. nov.: U. michauxii I. I. Tav.), Usnea cf. moreliana Motyka, U. parvula Motyka, U. steineri Zahlbr, U. subelegans (Vain.) B. de Lesd. (lectotype designated here), U. subparvula A. Gerlach & P. Clerc (characterized by spinulose fibrils and protocetraric acid in the medulla) and one as yet unidentified species (named Usnea sp. 1). Usnea cirrosa, U. cristatula and U. erinacea are new records for Brazil. A full description with morphological, anatomical (CMA and ascospores) and chemical features (TLC), as well as geographical distribution, is provided for each species along with an identification key to all species reported. Molecular data from the ITS rDNA, RPB1 and Mcm7 markers are present for most taxa, except for U. concinna, U. cristatula, U. kalbiana, U. lunaria, U. cf. moreliana and U. subelegans.

Phylogenetic analyses of nuclear (Mcm7, nrITS, nrLSU) and mitochondrial (mrSSU) DNA sequences revealed geographically disjunct lineages in Leptogium hibernicum. One of these lineages is described here as Leptogium krogiae, which differs from L. hibernicum in the thinner thallus (190–210 µm vs. 390–480 µm), shallowly striate lobes instead of deeply furrowed lobes, isidia that are seldom distinctly flattened, and apothecia with a subhymenial euparaplectenchymatous layer. Leptogium krogiae is a widespread epiphyte in mist-affected woodlands and montane forests in East Africa and appears to be a common species.

The new lichenized ascomycete Tapellaria palaeotropica is described from Mahé Island in the Seychelles. The species is characterized by a crustose, pale green, smooth thallus dispersed in patches and by having black, rounded apothecia with flat discs, hyaline, transversely, 3–5-septate ascospores and a purplish brown excipulum. Morphology, distribution and related species are discussed. A world key to all currently known species in the genus is presented.

The lowland area of southern Vietnam contains a high diversity of corticolous, crustose lichens, particularly in the family Graphidaceae. Two species, Acanthothecis verrucosa S. Joshi, Upreti & Hur and Graphis exuta S. Joshi, Upreti & Hur, are described new to science. Acanthothecis verrucosa is characterized by a verrucose, olive green thallus containing irregular to shortly lirellate apothecia, hyaline to brownish proper exciple apically lined by robust periphysoids, muriform ascospores, 30–70 × 15–20 μm, and the presence of psoromic and subpsoromic acids. Graphis exuta is characterized by a smooth, greenish white thallus, simple lirellae lacking thalline margin, entire labia coarsely white pruinose towards slit, muriform ascospores, 20–35×10–13 μm, and norstictic acid in the thallus. A new name, Acanthothecis yokdonensis S. Joshi & Hur, is proposed here for the species Acanthothecis salazinica S. Joshi & Hur, a later homonym of A. salazinica van den Boom & Sipman. In addition, 34 species from Vietnam are newly reported. A world key to the group of Graphis species characterized by short, simple and sessile lirellae lacking or with basal thalline margins (nuda-morph) is presented.

Lichens as sessile and slow-growing symbiotic associations have evolved various carbon-based secondary compounds (CBSCs) to mitigate the effects of some stressors in the extreme environments in which they often grow. The mat-forming lichen Cladonia stellaris, an important fodder for reindeer, produces usnic acid in the outermost layer and perlatolic acid in the medulla. Here, we studied effects of simulated global warming on these CBSCs in C. stellaris cultivated in climate chambers with: 1) ambient conditions as control or 2) ambient conditions +4°C. The chambers simulated, at an hourly resolution, an averaged 10-year growing season dynamic from a long-term monitored boreal mire in northern Sweden. After two months of acclimation, +4°C warming in one simulated growing season increased the concentration of usnic acid by 31% compared with ambient conditions, whereas the warming decreased the concentration of perlatolic acid by 14%. Since lichen CBSCs play important roles in ecosystem processes such as lichenivory and decomposition, these changes may profoundly affect lichen-dominated ecosystems.

The Trebouxia photobiont freshly isolated from Xanthoria parietina (L.) Th. Fr. was used to develop a live cell chondriome (mitochondrial DNA) labelling method. In the initial phase six candidate dyes were tested and compared for mitochondrial labelling utility as assessed by the signal to noise ratio (SNR) of the mitochondrial signal to the adjacent cellular background in standardized confocal images of 30 labelled cells. DIOC7, JC-1 and MitoTracker orange (MTO) dyes showed some labelling ability. MTO had significantly higher utility than the other dyes. In a second phase, MTO concentration was optimized. The final labelling protocol was a 30 minute incubation with 1 μM of MTO. The resultant labelling was suitable for both widefield and confocal microscopy. Both 2D thresholding and 3D volume construction are demonstrated using the resultant data. The protocol can therefore be utilized for both qualitative research and for quantitative measurement of the chondriome in Trebouxia photobionts. This will facilitate a wide range of mitochondrial investigations in lichenology.