This study re-examined the status of species of Diorygma Eshw. known from the Western Ghats using an integrative taxonomy approach that includes morphological and chemical data, as well as multigene phylogenetic analyses. Prior to this work, the two species D. karnatakense and D. dandeliense were distinguished primarily on lirellae morphology (branching pattern) and the number of ascospores per ascus. Our study of the morphology, chemistry and molecular phylogeny (mtSSU, LSU and RPB2) of freshly collected samples and re-examination of type material suggests that both names should be synonymized. Consequently, D. karnatakense is accepted as the correct name, with D. dandeliense as a newly proposed synonym. Phylogenetically, D. karnatakense is allied to D. antillarum and D. hieroglyphicum.

The algicolous and lichenicolous species Psammina filamentosa is described from the Netherlands and the UK, and is characterized by long (generally over 50 μm) and somewhat tapered conidial arms. Psammina filamentosa is compared with other Psammina specimens found in the same habitat, growing on algae or lichens on the dry side of trees and stones. Psammina filamentosa, P. inflata and P. stipitata differ in the dimensions of their conidial arms. Psammina simplex, however, may be a synonym of P. stipitata, and a DNA study is needed to determine whether it is a distinct species or developing material of P. stipitata. Psammina inflata is also reported as new for the Netherlands. A new worldwide key to the 10 species of Psammina currently known is provided, including three species described from plant material.

Cryptolechia carneolutea is the type species of the genus Cryptolechia, a rare taxon classified as endangered in the UK, now largely confined to ancient Fraxinus trees. The only tree with abundant growth of the species in one of its strongholds, the Slapton Ley National Nature Reserve in Devon, was blown over in a storm in April 2017, making it possible to collect material for molecular studies and transplant specimens to other Fraxinus trees in the area. The results of the phylogenetic analysis revealed C. carneolutea to be nested within the genus Gyalecta (Gyalectaceae). This further supports a broad circumscription of Gyalecta, after also including species previously placed in Belonia and Pachyphiale as proposed in other recent studies. It might be possible to introduce an alternative genus concept in Gyalectaceae, not schematically based on ascoma type and ascospore number, but presently not enough data are available to proceed with such a novel classification. A review of the taxonomic concept of Cryptolechia demonstrates that this name was used inconsistently in the past, and its possible inclusion in Gyalecta was anticipated by other authors. As the majority of species presently classified in Cryptolechia had been placed in Gyalecta before, only five new combinations are required to provide formal inclusion of all taxa in the latter genus: Gyalecta bicellulata (Kalb) D. Hawksw. & Lücking comb. nov., G. caudata (Kalb) D. Hawksw. & Lücking comb. nov., G. pittieriana (Kalb et al.) D. Hawksw. & Lücking comb. nov., G. saxatilis (Vězda) D. Hawksw. & Lücking comb. nov. and G. stellaris (Müll. Arg.) D. Hawksw. & Lücking comb. nov. We also supersede the previous lectotypification of Parmelia carneolutea Turner with the discovery of the holotype specimen in BM.

The results of the first molecular phylogenetic study of Pseudephebe are presented; a three-locus phylogeny. The genus is confirmed as monophyletic within the alectorioid clade of Parmeliaceae. Two major clades were recovered, which can be assigned to the two traditional taxa, P. minuscula and P. pubescens, with modifications of the species delimitation, especially the variable P. minuscula. These species are cryptic and cannot be confidently distinguished morphologically due to phenotypic convergence. Therefore, the use of P. pubescens aggr. is recommended for samples not molecularly analyzed. Contrary to previous studies, specimens of both species might have indistinct pseudocyphellae and also contain lichen substances; norstictic acid was detected in c. 60% of specimens tested. An SSU 1516 Group I intron is usually present in P. minuscula but always absent in P. pubescens. The species-level nomenclature is summarized and sequenced reference specimens (RefSpec) for both Pseudephebe species are selected. Sequences from Bryoria mariensis established that this name was a synonym of P. minuscula.

As part of a comprehensive revision of the Rhizocarpon geographicum species group using molecular and morphological approaches, we examined the name-bearing types of 15 species. We report ambiguities and inconsistencies with the reported features of some type specimens, original descriptions, and circumscriptions employed in keys for the identification of taxa within the complex. The reporting of chemical reactions and some morphological characters was found to be inconsistent and likely to lead to errors of identification. This is unfortunate in view of the widespread use of the complex in glaciology for lichenometry. Issues surrounding the typification of the basionym Lichen geographicus are clarified, and the epitype is illustrated. The complex nomenclatural situation regarding the name Rhizocarpon lecanorinum and its typification is also made clear. The examination of the anatomical and morphological characters presented here needs to be considered together with molecular phylogenetic information to provide a more informed new taxonomy of the group.

Bryoria araucana sp. nov. is described from Chile on the basis of morphological, chemical and molecular data. It has a grey to dark greyish brown pendent thallus with the base usually black, branching angles mainly obtuse, terminal branches with few lateral branchlets acutely inserted, fumarprotocetraric acid, and often protocetraric and confumarprotocetraric acids. It is morphologically similar to the Northern Hemisphere B. trichodes, but lacks soralia and has inconspicuous concolorous or slightly darker pseudocyphellae. Bryoria glabra is also reported for the first time from the Southern Hemisphere. New phylogenetic data based on ITS, mtSSU and MCM7 analyses suggest that Bryoria sect. Bryoria is polyphyletic and needs revision.

In order to confirm and investigate the extent of reported mismatches between chemotypes and molecular sequence data in Bryoria fuscescens s. lat., we examined 15 morphologically similar thalli from each of three Pinus forest sites in the Sistema Central of central Spain. Three thalli were rejected due to infections by Phacopsis huuskonenii (not previously published from Spain). The remaining 42 thalli represented nine ITS rDNA haplotypes and four chemotypes (by TLC): fumarprotocetraric and protocetraric acids; norstictic and connorstictic acids; psoromic acid; and fumarprotocetraric, protocetraric and psoromic acids. The molecular phylogenetic tree was characterized by extremely short branch lengths, often only with a single mutational difference, and a single haplotype could have different chemical products. In some cases, adjacent specimens represented different chemotypes, and three thalli appeared to be mixed individuals. Consistency of both molecular and chemical data within individual specimens was demonstrated by examining four different parts of each thallus, which showed only a difference in the location of psoromic acid in some. This is the first population-level study of this taxon, and so it is premature to propose taxonomic changes at this time. Further populations in different parts of the geographical range of this widespread complex now need to be analyzed, and more sensitive chemical analyses conducted, in order to understand the basis of the variability and determine the appropriate taxonomic treatment.

The new genus and species Bicoloromyces kyffinensis is described as new to science from a sterile crustose lichen, perhaps Lecanora fuscobrunnea or Lecidella sp. from Ebony Ridge of Mount Kyffin, Antarctica. The fungus recalls superficially the lichenicolous species referred to Taeniolella, but differs in having semi-macronematous conidiophores, tissues encrusted with calcium oxalate, aeruginose to blue-black colouration under the microscope, and conidia which are distoseptate and formed in basipetal chains. Energy dispersive spectroscopy established that the encrustations were of calcium oxalate. Differences from genera of rock-inhabiting fungi described from the Antarctic are discussed. This appears to be the furthest south any lichen-inhabiting fungus has been reported.

The original material of Sphinctrina tigillaris, collected in 1864, was relocated, re-examined, found to represent a species of Chaenothecopsis, and is transferred to that genus as C. tigillaris comb. nov. It occurred on a specimen of a polypore, now identified as Perenniporia meridionalis, on a beam in a Northamptonshire church, and does not appear to have been collected since. Perenniporia meridionalis is a predominantly central and southern European species which has not previously been recognized in the British Isles, although other English specimens have now been located in collections at Kew and referred to the related P. medulla-panis. The name Sphinctrina tigillaris had been overlooked since its original description in 1865, and is nomenclaturally distinct from Lichen tigillaris, the basionym of Cyphelium tigillare. Notes on five other calicioid fungi found on polypores, and a key to the six now known, are also included.

Recently, the number of cryptic species known has increased considerably, showing that species diversity has in many cases been underestimated in the past. Parmelia sulcata is a widely distributed species and one of the most common taxa in temperate Europe. The first intra-specific molecular studies on P. sulcata showed an unexpectedly high genetic variability. In the present work, we study the biodiversity of this taxon including specimens from four continents and using three molecular markers (nuITS, nuIGS rDNA, and partial β-tubulin gene). Two monophyletic groups of P. sulcata were encountered; one of these is epitypified as P. sulcata s. str and the other one is segregated as the new cryptic species P. encryptata sp. nov. Issues surrounding the lectotypification of Parmelia sulcata have also been elucidated.

This article traces the changing systems in the classification of the parmelioid lichens from the early 19th century to the present day. Molecular phylogenetic approaches have enabled the relative importance of traditionally used characters to be objectively re-assessed, and led to the realization of the significance of others that had previously been passed over or dismissed; for example, differences in ascospore and conidium types or the cell-wall constituents. Information on the different characters employed is presented and assessed. It is concluded that characters related to thallus form or chemical products prove to be less informative at the generic level than has sometimes been assumed. Features requiring further study are identified, and in the light of experience in this group, lichenologists should be cautious in translating their results into formal taxonomies.