The climate, geology and vegetation of Tasmania's South West wilderness are described briefly, with particular reference to lichens. One hundred and sixty-two lichens are recorded from alpine altitudes in the region and the major habitats for alpine lichens are discussed. The flora differs significantly from that of other Tasmanian mountain systems, and this is attributed in part to geology and macroclimate. The region is rich in Tasmanian endemics and distinctly austral species with restricted geographical distributions.

The new lichenicolous fungus Llimoniella cinnabarinae growing on Ramboldia cinnabarina from Alaska is described. The lack of excipular or epihymenial K+ purplish, violet or green pigments places it near the recently described L. phaeophysciae group. Its affinity with Llimoniella and other members of lichenicolous Helotiales is discussed.

Two new species in the lichen genus Atla, A. alaskana and A. recondita, are described. The ITS rDNA region is used for their molecular characterization. Morphologically, Atla alaskana is characterized by its rather thick and well-developed whitish grey thallus, and the rather large perithecia having a thalline excipulum. The presence of a thalline excipulum renders it similar to Sporodictyon species; however, in A. alaskana a distinct zone around the ostiolum is without a thallus and covered only by a thick white pruina. Atla recondita has a thin olivaceous brown thallus and moderately sized, emerging perithecia. It is not possible to identify this species unequivocally as an Atla species only by morphology, and it might well be mistaken for a Polyblastia. A key to all six Atla species, including the two new species, is provided.

Macentina stigonemoides sp. nov. is described from trees in Great Britain and Ireland; it is characterized by a filamentous to granular thallus with papillose cortical cells and pale perithecia with 3–5-septate spores.

Strigula confusa Fryday, Coppins & Common is described from the western British Isles, where it grows over bryophytes on mildly basic rocks. The concept of the genus Thelenella is expanded to include Chromatochlamys and the following new combinations are made: Thelenella larbalestieri (A. L. Sm.) Coppins & Fryday, Thelenella muscorum var. octospora (Nyl.) Coppins & Fryday, Thelenella vezdae (H. Mayrhofer & Poelt) Coppins & Fryday. Thelenella sordidula (Th. Fr.) H. Mayrhofer is reported for the first time from Europe (Svalbard).

A preliminary study of the Lecanora dispersa group in Argentina is presented. Two species (L. dispersa and L. hagenii) have been previously recorded and their known distribution is extended, one species (L. semipallida) is a new record from Argentina, and five taxa (L. flowersiana, L. persimilis L. torrida, L. wetmorei and L. zosterae var. zosterae) are reported for the first time from South America. Three species (L. albescens, L. crenulata and L. populicola) previously recorded for Argentina have not been confirmed as occurring in this country. Lecanora aff. fugiens is also treated and compared to the related species. The morphology, anatomy, secondary metabolites, distribution and ecology of the nine studied taxa are described and discussed, and a key to the taxa is included.

We describe Calicium sequoiae as a new species of lichenized Ascomycota from north-western California, USA. The species is distinguished morphologically from other known members of Calicium by its stalks that react I+ blue, mature ascospores that are ornamented with spiral ridges, and apothecia that produce prominent white pruina. It is also the only Calicium known to produce thamnolic acid as a major secondary substance. Sequences from the ITS-region showed C. sequoiae to be unique among calicioid Physciaceae, and phylogenetic analysis positioned it close to C. adspersum, C. chlorosporum, C. lenticulare, Cyphelium notarisii, and C. tigillare. Thus far, Calicium sequoiae has been collected only from old-growth redwood (Sequoia sempervirens) forests, where it occurred on thick, fibrous bark of large redwood trees. A key to the 12 species of Calicium known from the Pacific Northwest is provided.

Diploschistes albopruinosus is described as new to science. This species is found on siliceous rocks in La Caldera de Taburiente National Park (La Palma, Canary Islands). A description of the species is given together with notes on its chemistry, distribution, ecology and taxonomy. Related lichen taxa are discussed.

With 30 species, Tasmania is a major area of species diversity in the genus Menegazzia. Seven of these are new to science: M. abscondita Kantvilas, known from Tasmania and New Zealand, and M. athrotaxidis Kantvilas, M. hypogymnioides Kantvilas, M. petraea Kantvilas, M. ramulicola Kantvilas, M. subtestacea Kantvilas and M. tarkinea Kantvilas, all endemic to Tasmania. An identification key, descriptions based exclusively on Tasmanian collections, and detailed discussion of distribution, ecology, chemical composition and inter-species relationships are provided. All literature records of Menegazzia species pertaining to Tasmania are accounted for. New synonyms include: Menegazzia prototypica P. James and Parmelia pertusa var. coskinodes F. Wilson [synonyms of M. myriotrema (Müll. Arg.) R. Sant.], M. fertilis P. James [a synonym of M. platytrema (Müll. Arg.) R. Sant.] and Parmelia pertusa var. montana F. Wilson (a synonym of M. subtestacea). Incorrectly recorded species that should be deleted from the Tasmanian census include M. castanea P. James & D. J. Galloway (present on Macquarie Island) and M. testacea P. James & D. J. Galloway (endemic to New Zealand). The South American species, M. sanguinascens (Räs.) R. Sant., is recorded in Australasia (Tasmania) for the first time, whereas the widespread south-eastern Australian M. norstictica P. James is recorded for Western Australia. Salient features of the genus are discussed, including morphology, anatomy and chemistry. The biogeography of the genus is explored briefly. Twelve species (40%) are endemic to Tasmania, a level of endemism unmatched by any other species-rich genus on the island. Twelve species are shared with mainland Australia, eleven are shared with New Zealand, and only four species are shared with southern South America, all of which are sorediate, suggesting they are products of long-distance dispersal.

Bilimbia [Rheede] Rchb. (Oxalidaceae) is not validly published, whereby Bilimbia De Not. (Lichenes) is not a later homonym and must replace Myxobilimbia Hafellner. In an Appendix, the nomenclatural implications are acted upon: Bilimbia De Not. is re-instated and the new combination Bilimbia lobulata (Sommerf.) Hafellner & Coppins is made.

Chrysothrix occidentalis Elix & Kantvilas, C. palaeophila Kantvilas & Elix and C. tchupalensis Elix & Kantvilas are described as new to science. In addition, the new combination Chrysothrix sulphurella (Räsänen) Kantvilas & Elix is proposed, C. granulosa G. Thor is reported for the first time from Australia (including Tasmania) and New Zealand, and C. xanthina (Vain.) Kalb for the first time from Tasmania, Norfolk Island and New Zealand. A key to the Australian species of Chrysothrix is presented. Chemical data on non-Australasian species of the genus are also provided.

Two new lichenicolous ascomycetes, Corticifraga santessonii and C. chugachiana, are described from Lobaria and Nephroma species. The new species are readily distinguished by narrow ascospores and are known from the USA, Canada and Russia. A Table with the distinguishing characteristics of all known Corticifraga species is presented.

Szczazvinskia leucopoda Holien & Tønsberg and 5. foliicola Holien & Tønsberg are described from coastal Central Norway and Newfoundland, and from Papua New Guinea, respectively.

On the thalline lobes of Pyxine subdnerea there are delimited patches of pruina consisting of bipyramidal prisms, bipyramids and druses of weddellite, i.e. calcium oxalate dehydrate (COD), as revealed by X-ray analysis and SEM observations. The disappearance of the crystals from older thalline areas is preceded by an increase in the frequency of corrosion figures, in the form of etch square pits, and a decrease in the number of crystals occurring on the thalline surface. These features follow a dissolution gradient from the lobe apex towards the proximal edges of the patches. The corrosion figures are linked to the thermodynamic metastability of COD. Partial dissolution of the crystals, performed in water and in EDTA, has confirmed this latter assumption. It is thought that the disappearance of pruina, which interferes with the transmission of light to the algal layer, may allow the formation of soredia in mature thalline portions.

A description is given for Cetraria obtusata (Schaerer) v. d. Boom & Sipman, comb, et stat. nov., known so far only from the central Alps, and characterized by a pale yellow, C+ yellowish orange medulla and raised pseudocyphellae often surrounded by projections. It contains the rare lichen substance secalonic acid C and two unidentified substances.