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SummaryWe studied the evolutionary history of the Parmeliaceae (Lecanoromycetes, Ascomycota), one of the largest families of lichen-forming fungi with complex and variable morphologies, also including several lichenicolous fungi. We assembled a six-locus data set including nuclear, mitochondrial and low-copy proteincoding genes from 293 operational taxonomic units (OTUs).The lichenicolous lifestyle originated independently three times in lichenized ancestors within Parmeliaceae, and a new generic name is introduced for one of these fungi. In all cases, the independent origins occurred c. 24 million yr ago. Further, we show that the Paleocene, Eocene and Oligocene were key periods when diversification of major lineages within Parmeliaceae occurred, with subsequent radiations occurring primarily during the Oligocene and Miocene.Our phylogenetic hypothesis supports the independent origin of lichenicolous fungi associated with climatic shifts at the Oligocene-Miocene boundary. Moreover, diversification bursts at different times may be crucial factors driving the diversification of Parmeliaceae. Additionally, our study provides novel insight into evolutionary relationships in this large and diverse family of lichen-forming ascomycetes.

A three-dimensional compositional pattern in the epiphytic lichen vegetation in Tasmanian cool temperate rainforest is demonstrated using the robust ordination technique, hybrid multidimensional scaling (HMDS). The first two dimensions are correlated with the age of the host tree (and the concomitant change in bark texture) and wetness of the substrate. No measured environmental variable is related to the third dimension, which is tentatively attributed to a gradient in the constancy of the microclimate. Pattems of richness of lichen growth forms and the cover of bryophytes are correlated with the three putative environmental gradients. Possible successional trends between 12 community groups derived by numerical classification are described with respect to changes in substrate age, wetness and microclimatic constancy. Temporal variation of these factors due to tree growth, together with the slow establishment and long persistence of some lichen species, make succession in epiphytic communities very complex. This study demonstrates the value of HMDS in identifying compositional patterns and generating hypotheses about the causal ecological factors. The existence of the postulated microclimatic constancy gradient was not appreciated before the analysis and its discovery illustrates the risk of relying on constrained ordination methods, such as canonical correspondence analysis.

Nomenclatural type definitions are one of the most important concepts in biological nomenclature. Being physical objects that can be re-studied by other researchers, types permanently link taxonomy (an artificial agreement to classify biological diversity) with nomenclature (an artificial agreement to name biological diversity). Two proposals to amend the International Code of Nomenclature for algae, fungi, and plants (ICN), allowing DNA sequences alone (of any region and extent) to serve as types of taxon names for voucherless fungi (mainly putative taxa from environmental DNA sequences), have been submitted to be voted on at the 11th International Mycological Congress (Puerto Rico, July 2018). We consider various genetic processes affecting the distribution of alleles among taxa and find that alleles may not consistently and uniquely represent the species within which they are contained. Should the proposals be accepted, the meaning of nomenclatural types would change in a fundamental way from physical objects as sources of data to the data themselves. Such changes are conducive to irreproducible science, the potential typification on artefactual data, and massive creation of names with low information content, ultimately causing nomenclatural instability and unnecessary work for future researchers that would stall future explorations of fungal diversity. We conclude that the acceptance of DNA sequences alone as types of names of taxa, under the terms used in the current proposals, is unnecessary and would not solve the problem of naming putative taxa known only from DNA sequences in a scientifically defensible way. As an alternative, we highlight the use of formulas for naming putative taxa (candidate taxa) that do not require any modification of the ICN.

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The genus Mycoblastus in cool temperate latitudes of the Southern Hemisphere is reviewed.

Abstract96 macrolichens, including 12 new records, are reported for cool temperate rainforests in Tasmania. These species belong mainly to the austral cool temperate element. A descriptive account of the lichen floras from five major rainforest communities is given. Field observations suggest that substrate and light are the most important ecological factors affecting the distribution of lichens in rainforest. Although most species are widespread in Tasmania, large-scale disturbance and the fragmentation of rainforest stands is seen as a threat to their survival.

The Tasmanian species of the family Thelotremataceae with thin-walled ascospores and exfoliating, chroodiscoid apothecia are studied in detail. Problems in the delimitation of genera are discussed, and characters such as the morphology of the apothecia, structure and form of the exciple, presence of periphyses, ascus structure, ascospore morphology and thallus chemistry are evaluated. The concept of the typically foliicolous genus Chroodiscus (Müll. Arg.) Müll. Arg. is expanded to include corticolous and terricolous species, and the new taxa C. asteliae Kantvilas & Vězda, C. australis Kantvilas & Vězda, C. australis subsp. tasmanicus Kantvilas & Vězda, C. lamelliferus Kantvilas & Vězda and C. minor Kantvilas & Vězda are described and illustrated. The related Australasian species, C. megalophthalmus (Müll. Arg.) Vězda & Kantvilas is also treated. Two new genera are also described. Pseudoramonia Kantvilas & Vězda, based on the Venezuelan species, P. stipitata (Vězda & Hertel) Kantvilas & Vězda, is introduced to accommodate P. richeae Kantvilas & Vězda; Topeliopsis Kantvilas & Vězda is described to include the Tasmanian taxa, T. muscicola Kantvilas & Vězda and T. rugosa Kantvilas & Vězda, and the North American species T. toensbergii Vězda & Kantvilas.