A standardized morphological terminology and descriptive scheme for the sterile asexually reproducing genus Lepraria s. lat. is presented. The contribution includes observations on development and ontogeny of morphological structures and is extensively illustrated with scanning electron and light micrographs. Lepraria has long been considered to be devoid of morphological characters, however the results of extensive micro- and macro-morphological studies strongly refute this hypothesis. The morphological structures of the thallus are defined and described based on their varying degrees of complexity. Thalline morphological variability in the group is categorized into two major types that are further subdivided into six subtypes. Each subtype is described and an artifical key to the subtypes is provided.

The diminutive species Micarea capitata is described from north-western Sweden. It has been found at two localities in boreal forests where it grew on the bryophyte Hylocomium splendens. Micarea capitata is distinguished by small (0·10–0·35 mm diam.) black apothecia, (0–)1-septate ascospores and a mottled, darkly pigmented hypothecium.

Tremella macrobasidiata is a proposed new species for a lichenicolous heterobasidomycete strictly parasitizing the hymenium of Lecanora chlarotera. It is reported from Spain, and is characterized by large and particularly variable basidia, rather large basidiospores and the production of asteroconidia, forming brownish to dark green galls in the specific host apothecia. The presence of asteroconidia is discussed. Comparisons with closely related lichenicolous Tremella species are also provided.

The study of the type and additional material of Buellia andicola, B. hypophana and B. reagens has shown that these taxa are conspecific with B. thiopoliza. Buellia thiopoliza is a muscicolous species growing at middle to high altitudes in the mountains of both hemispheres. It is easily recognized by its K+ purple-red yellow pigment mainly concentrated in the hypothecium, and by the presence of xanthones in the thallus and the apothecial tissues. The new combination Tetramelas thiopolizus is proposed. A key to all known Tetramelas species is included. The also muscicolous Buellia hypoleuca is reduced to synonymy with Phaeorrhiza sareptana var. sphaerocarpa.

This study focuses on European Usnea species with sorediate shrubby thalli, with the aim to evaluate the morphological and chemical separation of species in the light of molecular data. Twenty-two Usnea species, including widely distributed taxa such as U. diplotypus, U. fulvoreagens, U. glabrescens, U. lapponica, U. subfloridana, U. substerilis and U. wasmuthii, were included in the study using Bayesian and maximum parsimony analyses of nuclear ITS and beta-tubulin sequences. The analyses showed that: 1) most taxa that are morphologically well delimited are also distinct by means of molecular characters, 2) shrubby taxa in the section Usnea that are difficult to determine by traditional characters form a group of closely related but still genetically distinct entities, except U. diplotypus and U. substerilis which appear to be polyphyletic. The branch lengths differed largely between two parts of the ITS tree (sections Usnea and Ceratinae). Usnea intermedia is proposed as the sexually reproducing counterpart for the sorediate U. lapponica. Additionally, some new chemotypes of Usnea species were determined.

The crustose lichen genus Mycoblastus in the Northern Hemisphere includes eight recognized species sharing large, simple ascospores produced 1–2 per ascus in strongly pigmented biatorine apothecia. The monophyly of Mycoblastus and the relationship of its various species to Tephromelataceae have never been studied in detail. Data from ITS rDNA and the genes coding for translation elongation factor 1-α and DNA replication licensing factor mini-chromosome maintenance complex 7 support the distinctness of Mycoblastus s. str. from the core of the Tephromelataceae, but recover M. fucatus and an undescribed Asian species as strongly supported within the latter group. We propose accommodating these two species in a new genus, Violella, which is characterized by its brownish inner ascospore walls, Fucatus-violet hymenial pigment granules and secondary chemistry, and discuss the position of Violella relative to Calvitimela and Tephromela. We describe the new species Violella wangii T. Sprib. & Goffinet to accommodate a new species with roccellic acid from Bhutan, China, India and the Russian Far East. We also exclude Mycoblastus indicus Awasthi & Agarwal from the genus Mycoblastus and propose for it the new combination Malmidea indica (Awasthi & Agarwal) Hafellner & T. Sprib.

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.

Hemithecium isidiatum from the Eastern Himalayas is described as new to science. It is the first isidiate species in the genus Hemithecium and is otherwise characterized by hyaline muriform ascospores and the presence of salazinic acid.

Graphis parvicarpa and Pallidogramme bengalense are described as new to science from India. Graphis parvicarpa is characterized by a striate excipulum, inspersed hymenium, muriform ascospores, and norstictic acid in the thallus. Pallidogramme bengalense is characterized by a striate exciple, muriform, hyaline to pale brown ascospores, inspersed hymenium and no lichen substances in the thallus.