The new genus Imsharria is proposed for a crustose species found on or near mountain summits on the Falkland Islands. It is separated from other genera of Lecideaceae by a combination of Porpidia-type asci, halonate ascospores, immersed apothecia and a hyaline hypothecium, and forms a distinct branch in the phylogenetic analysis using the markers nrITS and mtSSU. The single species, I. orangei, is characterized by its innate apothecia with a brown disc and a thallus containing norstictic acid and an amyloid (I+ violet) medulla. In addition, Porpidia imshaugii is described for a species from the Falkland Islands resembling P. skottsbergiana but with larger ascospores, and Porpidia navarina is shown to belong in the genus Poeltiaria, with the new combination Poeltiaria navarina being made. A key to the Lecideaceae on the Falkland Islands is provided.

The new species Aspicilia malvinae is described from the Falkland Islands. It is the first species of Megasporaceae to be discovered on the islands and only the seventh to be reported from South America. It is distinguished from other species of Aspicilia by the unusual secondary metabolite chemistry (hypostictic acid) and molecular sequence data. The collections of the new species support two lichenicolous fungi: Endococcus propinquus s. lat., which is new to the Falkland Islands, and a new species of Sagediopsis with small perithecia and 3-septate ascospores c. 18–20 × 4–5 μm, which is described here as S. epimalvinae. A total of 60 new DNA sequences obtained from species of Megasporaceae (mostly Aspicilia) are also introduced.

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.

Lichens are widely acknowledged to be a key component of high latitude ecosystems. However, the time investment needed for full inventories and the lack of taxonomic identification resources for crustose lichen and lichenicolous fungal diversity have hampered efforts to fully gauge the depth of species richness in these ecosystems. Using a combination of classical field inventory and extensive deployment of chemical and molecular analysis, we assessed the diversity of lichens and associated fungi in Glacier Bay National Park, Alaska (USA), a mixed landscape of coastal boreal rainforest and early successional low elevation habitats deglaciated after the Little Ice Age. We collected nearly 5000 specimens and found a total of 947 taxa, including 831 taxa of lichen-forming and 96 taxa of lichenicolous fungi together with 20 taxa of saprotrophic fungi typically included in lichen studies. A total of 98 species (10.3% of those detected) could not be assigned to known species and of those, two genera and 27 species are described here as new to science: Atrophysma cyanomelanos gen. et sp. nov., Bacidina circumpulla, Biatora marmorea, Carneothele sphagnicola gen. et sp. nov., Cirrenalia lichenicola, Corticifraga nephromatis, Fuscidea muskeg, Fuscopannaria dillmaniae, Halecania athallina, Hydropunctaria alaskana, Lambiella aliphatica, Lecania hydrophobica, Lecanora viridipruinosa, Lecidea griseomarginata, L. streveleri, Miriquidica gyrizans, Niesslia peltigerae, Ochrolechia cooperi, Placynthium glaciale, Porpidia seakensis, Rhizocarpon haidense, Sagiolechia phaeospora, Sclerococcum fissurinae, Spilonema maritimum, Thelocarpon immersum, Toensbergia blastidiata and Xenonectriella nephromatis. An additional 71 ‘known unknown’ species are cursorily described. Four new combinations are made: Lepra subvelata (G. K. Merr.) T. Sprib., Ochrolechia minuta (Degel.) T. Sprib., Steineropsis laceratula (Hue) T. Sprib. & Ekman and Toensbergia geminipara (Th. Fr.) T. Sprib. & Resl. Thirty-eight taxa are new to North America and 93 additional taxa new to Alaska. We use four to eight DNA loci to validate the placement of ten of the new species in the orders Baeomycetales, Ostropales, Lecanorales, Peltigerales, Pertusariales and the broader class Lecanoromycetes with maximum likelihood analyses. We present a total of 280 new fungal DNA sequences. The lichen inventory from Glacier Bay National Park represents the second largest number of lichens and associated fungi documented from an area of comparable size and the largest to date in North America. Coming from almost 60°N, these results again underline the potential for high lichen diversity in high latitude ecosystems.

The new species Psoroma nivale is described from an area of late snow-lie in the Keglo Bay area on the eastern side of Ungava Bay, northern Québec, Canada. It is superficially similar to P. hypnorum but has a dark, brownish black thallus colour without reddish hues, much-branched, proliferating squamules, thick paraphyses, distinct but inconspicuous IKI+ ascus tube structures, and characteristic elongate, bacilliform, often asymmetrical ascospores. The new species is compared with possible related taxa and its systematic position discussed. A key to the species of pannarioid lichens reported from arctic areas of North America is also provided.

The new lichen species Lecidea phaeophysata is described from rocks close to the coast in Italy, Portugal, France and Ireland. Distinguishing features include Porpidia-type asci and simple paraphyses that are fuscous brown pigmented in their upper section. Its systematic position is discussed but is unclear as molecular data are lacking (all collections are c. 20 years old). Therefore, we chose to describe the species in a broadly-circumscribed Lecidea rather than erecting a new monotypic genus. A key to saxicolous lecideoid lichens present on Atlantic coasts in Europe is also provided.

Eleven new species of crustose, lichenized fungi are described from the Falkland Islands (Islas Malvinas). Nine species are saxicolous, whereas Lecania vermispora occurs on the stems of Hebe elliptica and Tephromela lignicola is lignicolous on fence posts. The new species are: Bacidia marina, with a sordid blue-green K−, N+ violet epihymenium and acicular, multiseptate ascospores; B. pruinata, with pruinose apothecia and multiseptate ascospores; Buellia gypsyensis, with a thallus containing 5-O-methylhiascic acid and with Amandinea-type conidia; Cliostomum albidum, with pruinose apothecia lacking pigments; C. longisporum, with long narrow ascospores (c. 20 × 3 µm); Coccotrema rubromarginatum, with a placodioid thallus having a red-brown margin and lower surface; Hymenelia microcarpa, with minute, immersed apothecia (<0·1 mm diam.) and a trebouxioid photobiont; Lecania vermispora, with vermiform, 3–6 septate ascospores; Lepra argentea, with papillate isidia with dark caps; Rhizocarpon malvinae, which is similar to R. reductum but with a grey thallus, generally sessile apothecia with a thick raised margin and often with the Cinereorufa-green pigment in the epithecium and upper exciple; and Tephromela lignicola, a sterile, sorediate species on fence posts. Most of these species are reported only from the Falkland Islands although Coccotrema rubromarginatum is also reported from Isla de los Estados and Isla Grande de Tierra del Fuego, Argentina. Ascoconidia are reported from Lepra argentea and cephalodia from Pertusaria pachythallina. Keys to the species reported from the Falkland Islands in the genera of the newly described species are also provided.

Numerous recent studies of lichenized fungi have uncovered hidden genetic diversity within a single phenotypic entity (so-called ‘cryptic species’). Here we report the opposite situation with vastly different morphologies apparently deriving from the same genotype. Endocena is a monotypic genus known only from southern South America. The single reported species, the terricolous E. informis, is morphologically variable; the type and other collections from the west coast of Chile being subfruticose, whereas specimens from further south and east are almost crustose in form. A sorediate terricolous lichen that is frequent on the Falkland Islands was confirmed by phylogenetic analysis of ITS rDNA and mtSSU rDNA sequences as being congeneric with E. informis and, surprisingly, both taxa were recovered as congeneric with the recently described genus and species Chirleja buckii, which is morphologically distinct from both E. informis and the sorediate taxon. Consequently, the genus Chirleja is included in the synonymy of Endocena and the new combination Endocena buckii is proposed. Because E. informis and the sorediate specimens have a similar thallus structure that differs radically from that of E. buckii, the name E. informis var. falklandica is proposed for the sorediate taxon. Poorly developed, incipient apothecia are also described from both varieties of E. informis, the first time that these have been reported for Endocena. We also report two lichenicolous fungi from E. informis var. informis, which are the first reports of lichenicolous fungi occurring on this genus.

The new species Xenolecia cataractarum Fryday is described from Campbell Island. It differs from X. spadicomma, the only other species of the genus, in having much smaller apothecia and ascospores, an olivaceously pigmented epihymenium (brown in X. spadicomma), and a thallus with a non-amyloid medulla and norstictic acid (amyloid medulla and confluentic acid in X. spadicomma). Xenolecia spadicomma is reported here from several localities on the Falkland Islands and three from the Región de Los Lagos, Chile, which are the first reports of this species since its description from Isla Wellington in the south-west of Patagonia in 1868. A full description of X. spadicomma is also provided.

The new species Austrella isidioidea, which is unique in the genus in having isidioid structures on the thallus lobe ends as well as apothecia lacking a thalline margin, is described from the Falkland Islands. A collection with an identical mtSSU rDNA sequence to A. arachnoidea but with significant morphological differences (viz. a variable apothecial margin ranging from an arachnoid hyphal weft to a corticated regular margin) is reported from Îles Kerguelen. The phylogenetic and biogeographical implications of these new records are discussed.

A new Arthothelium species, A. hymeniicola in the apothecia of an unidentified Bacidia sp., is described from Campbell Island, New Zealand. The new species is remarkable, not only by being the first lichenicolous Arthothelium species, but also by being an endohymenial fungus not forming ascomatal structures. Previously, no Arthoniaceae species were reported as parasitic from Bacidia spp. However, both generic and family placements are tentative and the possibility of a placement in the Cookellaceae is also discussed. Differences between Arthoniaceae and Cookellaceae, and the generic delimitations within them, are generally based on the structures of the fruiting bodies, rendering the taxonomic placement of the new species challenging without molecular data; neither fruiting bodies nor molecular data are available for the new species and the Cookellaceae.

Eight new species of Lecideaceae are described from the southern subpolar region: Bryobilimbia coppinsiana Fryday, a saxicolous species with one septate ascospores (Campbell Island, New Zealand); Immersaria fuliginosa Fryday, with a thallus composed of thalloconidia (Falkland Islands); Lecidea aurantia Fryday, with an orange thallus (Auckland Islands, New Zealand); L. campbellensis Fryday, with an endolithic thallus and apothecia resembling those of a species of Porpidia (Campbell Island); Poeltiaria ochyrae Hertel, which is similar to P. subincongua but with a thick areolate thallus (South Orkney and South Shetland Islands); P. tasmanica Fryday, which is similar to P. urbanskyana but with smaller ascopores (Tasmania); Poeltidea inspersa Fryday with an enolithic thallus and a hymenium with large oil globules (Falkland Islands); and Porpidia vulcanoides Hertel & Fryday with immersed apothecia with a thick margin and large ascospores (SW Chile). Lecidea kalbii Hertel is resurrected from the synonymy of L. mannii Tuck. and treated as a distinct species. The circumscription of genera within the Lecideaceae is also discussed: Poeltiaria is shown to be heterogeneous, and the genera Labyrintha and Notolecidea are reduced to synonymy with Poeltidea and Poeltiaria respectively, and the new combinations Poeltidia implexa (Malcolm et al.) Hertel & Fryday and Poeltiaria subcontinua (Hertel) Hertel & Fryday made. A key to the genera of Lecideaceae s. lat. is provided.

The new generic name Bryobilimbia is proposed for Lecidea hypnorum and the closely related taxa Lecidea ahlesii var. ahlesii, L. ahlesii var. nemoralis, L. diapensiae, L. sanguineoatra and Mycobilimbia australis. A phylogenetic analysis based on five genes shows that Lecidea berengeriana does not belong to this group but is more closely related to Romjularia. Both groups of species have been included in Mycobilimbia by some authors but are instead shown to be most closely related to a group of genera (including Clauzadea, Farnoldia, Lecidoma and Romjularia) that do not belong to Lecideaceae s. str. A neotype is selected for Lichen sanguineoater Wulfen and the new combinations Bryobilimbia ahlesii var. ahlesii, B. ahlesii var. nemoralis, B. australis, B. diapensiae, B. hypnorum and B. sanguineoatra are proposed. A lectotype is also selected for L. templetonii Taylor.

The new taxa Cliostomum subtenerum, Dactylospora suburceolata, Fuscidea oceanica, Lecania granulata, Lecidea herteliana, and Ropalospora lugubris f. sorediata are described from collections made from Scotland and Wales. Outside the British Isles, D. suburceolata is also known from Switzerland, L. herteliana from NE North America and R. lugubris f. sorediata from Sweden and NE North America. In addition, Lecidea luteoatra Nyl. belongs to the Lecanora marginata group and the name Lecanora viridiatra (Stenh.) Nyl. is taken up for this species, Peterjamesia sorediata is transferred to Roccellographa, and Ropalospora atroumbrina is included in the synonymy of R. lugubris f. sorediata.

Although several lichen inventories exist for European ultramafic sites, only four surveys of serpentine lichens for North America have been published to date. Of those, only one has been conducted in California. We conducted a survey of saxicolous lichens from ultramafic rocks (including nephrite, partially serpentinized peridotite, and serpentinite) and non-ultramafic rocks (including silica-carbonate, shale, and sandstone) at the New Idria serpentinite mass, San Benito County, California. X-ray Fluorescence Analysis of the rocks from which the lichens were collected revealed significant elemental differences between the ultramafic and non-ultramafic rocks for 26 of the 32 major and trace elements analyzed. We identified a total of 119 species of lichenized and lichenicolous fungi; 60 species were restricted to ultramafic substrata, 19 to silica-carbonate, and 15 to shale and sandstone. Only 4 species were shared in common. A permutational multivariate analysis of variance (perMANOVA) test revealed significant differences in lichen assemblages between ultramafic and non-ultramafic rocks at the species level but not at the generic level, with species richness (alpha-diversity) significantly greater at the ultramafic sites. We suggest that, although differences in geochemistry clearly influence the lichen community composition, other factors, especially substratum age and the physical characteristics of the rock, are of equal, if not greater, importance. Of all the species collected, six, Buellia aethalea, B. ocellata, Caloplaca oblongula, Rhizocarpon saurinum, Thelocarpon laureri, and Trapelia obtegens, are reported new to California, along with an apparently previously undescribed Solenopsora sp. The rest of the species encountered are relatively frequent in the lichen flora of southern and central California, except Aspicilia praecrenata, a rare California endemic that we collected on both ultramafic and non-ultramafic rocks.

Ten new species in nine different genera are described from the Falkland Islands (Islas Malvinas): Bryonora granulata with a finely granular thallus containing perlatolic acid; Bryoria mariensis, a terricolous species with norstictic acid and unusual cortex cells; Carbonea hypopurpurea with a K+ purple hypothecium and a thallus containing confluentic and 2′-O-methylperlatolic acids; Caloplaca megalariicola lichenicolous on Megalaria grossa; Cladonia flammea with a red-orange coloration on the lower side of the primary squamules; Cliostomum falklandicum, on rocks and with a dispersed thallus containing only atranorin; Lepraria malouina with usnic and stictic acids; Rimularia andreaeicola, over bryophytes and lacking lichen substances; R. subpsephota, similar to R. psephota but with a discrete white thallus lacking norstictic acid; and Usnea austrocampestris, a straggling species in sect. Neuropogon from the mountain tops. Rimularia andreaeicola is also known from Tierra del Fuego and R. subpsephota from Tierra del Fuego and South Georgia, but the other species are known only from the Falkland Islands. The new combinations Carbonea agellata, C. subdeclinans, Cliostomum aeruginascens and C. violascens are also made; Lecidea interrupta Darb. and Lecidea protracta Darb. are reduced to synonymy with Lecanora xantholeuca (Müll. Arg.) Hertel; Rhizocarpon simillimum is reported for the first time from the Southern Hemisphere, from the Falkland Islands and New Zealand; and Bryoria chalybeiformis is reported for the first time from the Falkland Islands.