The Caloplaca crenulatella species complex is monophyletic, based on analysis of ITS nrDNA sequences. It is characterized mainly by its ascospores and a simplified thallus. Caloplaca aquensis, C. borysthenica, C. interfulgens, C. lactea, C. marmorata and C. tominii represent well-defined monophyletic lineages within it. Caloplaca diffusa, described here as a new species, is a well-supported lineage with a distinctive phenotype. Caloplaca crenulatella s. lat. and C. ferrarii s. lat. are heterogeneous taxa appearing in four and two places respectively within our tree. Caloplaca ochracea also belongs to the group, although it has different ascospore characters. Caloplaca gyalolechiaeformis and C. pseudocitrina are later synonyms of C. tominii. Arctic and North American sorediate specimens morphologically very close to C. tominii represent a separate lineage recently recognized as C. erichansenii. The North American Caloplaca nashii has a C. crenulatella-like phenotype but does not belong to the C. crenulatella complex. The identities of Caloplaca lacteoides and Caloplaca epigaea are not clear, but the latter may be a terricolous ecotype of one of the entities within C. crenulatella s. lat. A key to the European species of the group is provided.

Eleven species are recognized of which C. bogilana and C. subflavorubescens are described here as new to science while nine species (C. cinnabarina, C. decipiens, C. ferruginea, C. inconspecta, C. pellodella, C. scopularis, C. stantonii, C. squamosa and C. subsoluta) are reported for the first time for South Korea. Both new species are peculiar due to their secondary chemistry; anthraquinones along with atranorin, gyrophoric acid and lecanoric acid in C. bogilana, and gyrophoric acid together with anthraquinones in C. subflavorubescens.

The fine-scale genetic variation and population structure of lichen-forming fungi is little known and sampling strategies are rarely recommended or discussed. I tested if the sample sizes of molecular data sets used in recent population studies of Xanthoria parietina revealed all haplotypes potentially present and, accordingly, quantified how many haplotypes were potentially missing in the samples. Data sets were concatenated from two geographical regions in Scandinavia and investigated if the sampling reached saturation at two levels: 1) individual-based using rarefaction curves and 2) population-based using species accumulation curves. At both levels, the matrices of two molecular markers (IGS and ITS) were analysed separately. The molecular markers show similar and parallel patterns in all analyses. Rarefaction analyses did not reveal different patterns for populations in different habitats, i.e., bark and rock. Species accumulation curves estimated with the Chao 1 richness estimator indicated that 23% of the IGS and 8% of the ITS haplotypes were not detected. Corresponding figures from an abundance-based coverage estimator (ACE) were 37% and 18%. Pilot studies are recommended to determine appropriate sample sizes for genetic-based population studies of lichen-forming fungi.

Twenty-three species of epiphytic Caloplaca are recognized in India, of which Caloplaca himalayana Joshi, Y. & Upreti, characterized by thin, continuous, yellowish thallus, numerous ferruginous-red to brownish red, flat to subconvex apothecia with a persistent proper margin and lignicolous habitat, is described here as a new species. Because of the ferruginous coloured apothecial disc, the new species is provisionally placed in the ferruginea group until a taxonomic treatment of the whole group has been carried out. The ferruginea group is characterized by a whitish to grey (rarely yellowish) crustose thallus, a ferruginous to rarely blackish apothecial disc, biatorine to lecanorine exciple, thick-walled spore septa and the chemosyndrome C. The taxonomic affinities of the new taxa with several other taxa, including species of ferruginea group, are discussed. Two new records for India are also recorded: Caloplaca alnetorum Giralt, Nimis & Poelt and C. crocea (Kremp.) Hafellner & Poelt. A key to all the corticolous Caloplaca species occurring in the Indian subcontinent is also provided.

Three new species of the lichen genus Caloplaca (Teloschistaceae) from India are described. Caloplaca jatolensis belongs to the Triophthalmidium section, while C. pseudisteroides and C. subleptozona belong to the Sideritis group.

The xanthorioid taxa Xanthomendoza borealis and Xanthoria mawsonii are revised using morphological, anatomical, secondary chemical, and molecular characters. We conclude that most specimens determined as X. mawsonii from the Antarctic are conspecific with specimens labelled X. borealis from the Northern Hemisphere. Some specimens named X. mawsonii from the Antarctic are wrongly determined specimens of Xanthoria candelaria (L.) Th. Fr, including the holotype of Xanthoria mawsonii C. W. Dodge. Accordingly, Xanthoria mawsonii C. W. Dodge is a synonym to Xanthoria candelaria (L.) Th. Fr. The only available correct name for the bipolar species, which comprises material previously determined as X. borealis and X. mawsonii, and is distinct from the more widespread taxon X. candelaria, is Xanthomendoza borealis (R. Sant. & Poelt) Søchting, Kärnefelt & S. Kondratyuk.

Caloplaca subalpina Vondrák, Šoun & Palice and C. thracopontica Vondrák & Šoun are described here as new to science. The former is a sorediate, often sterile, saxicolous species inhabiting subalpine base-rich overhanging rocks in European mountains; the latter grows on maritime cliffs of the Black Sea and is conspicuous by the lobules and pustules which are usually present on its thallus and by its apothecia which are typically large and abundant. The placing of the two species in the C. cerina group was confirmed by molecular studies using nrDNA ITS sequences. The chemosyndromes of both new species correspond to chemosyndrome A, which is in accordance with their position in the C. cerina group. A key to the saxicolous species of the C. cerina group is provided.

Three new Xanthoria species are described from South Africa. Xanthoria hirsuta sp. nov. has hairs on the surface of the thallus and apothecia, best visible in young, growing parts. Dust particles and sand granules stick to this hairy surface, giving the thallus a somewhat dirty appearance. Xanthoria inflata sp. nov. has inflated lobes similar to a Menegazzia. It carries numerous crystals on its medullary hyphae, which are ivory-coloured in young, but intensely orange coloured in old lobes. Xanthoria doidgeae sp. nov. has relatively small lobes with pruinose margins. All three species are fertile, none of them forms symbiotic propagules.

In order to examine genetic variation and population structure of the widespread lichen-forming ascomycete Xanthoria parietina from similar habitats, but different sites in Scandinavia, we investigated seven populations in Scania, southernmost Sweden, and compared the results with a corresponding study on Storfosna, central Norway. Sequence variations of the nuclear ribosomal DNA were used as molecular markers, for both a part of the IGS region and the complete ITS1-5.8S-ITS2 region. The amount of genetic variability observed was comparable in the two investigations. Divergence between populations in different habitats found in the previous study was also present in this study. Xanthoria parietina is genetically differentiated between habitats with no evidence of restricted gene flow between populations in the same habitat at the present spatial scale, at least at sites along the coast of Scandinavia. Differentiation between habitats is considerable at both study sites, which we attribute to restricted gene flow between habitats, i.e. habitat isolation.

The type material of Physciamagara Kremp., which is the type species of Seirophora Poelt (Teloschistaceae), is shown to be heterogeneous. It is a mixture of Teloschistesvillosus (Ach.) Norman and Ramalinamaciformis (Delile) Bory. Physciamagara Kremp. is typified on the T. villosus-part. Teloschistes species with multiseriate hairs, spores with short septa, thick and strongly conglutinated cortex hyphae with thick walls, lacking cilia or rhizines, and which have a mainly northern hemispheric distribution, are transferred to Seirophora. The following new combinations are made: Seirophora aurantiaca (R. Br.) Frödén, Seirophora austroarabica (Sipman) Frödén, Seirophora californica (Sipman) Frödén, Seirophora contortuplicata (Ach.) Frödén, Seirophora lacunosa (Rupr.) Frödén, Seirophora scorigena (Mont.) Frödén, Seirophora stenophylla (Tav.) Frödén, and Seirophora villosa (Ach.) Frödén.

Phoma fuliginosa sp. nov. is described and illustrated from apothecia of Caloplaca trachyphylla (Teloschistaceae) collected in Nebraska, USA. The species is distinguished from other lichenicolous fungi referred to the genus in the shape and size of the conidia. It is considered pragmatic to continue to use the generic name Phoma for this group of lichenicolous coelomycetes until cultural and molecular information is available, although these fungi may later prove not to be congeneric amongst themselves nor with the species occurring on plants. A key to the 14 lichenicolous species now accepted in Phoma is provided, and notes on reports of some additional collections referred to the genus are included.

Hueidea australiensis Kantvilas & P.M. McCarthy gen. et sp. nov. (Fuscideaceae) is described from seasonally inundated, granite rocks in the Mt Kosciuszko area of New South Wales, Australia. The genus is characterized by the crustose habit, a green unicellular photobiont of the type found in the Fuscideaceae, Teloschistes-type, eight-spored asci, non-adhering, simple paraphyses and polarilocular, hyaline ascospores. Its systematic position is discussed, based on a comparative study of a range of related or superficially similar taxa from the Teloschistaceae and Fuscideaceae.