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Abstract:New records of 15 Lepraria species from South America are presented. Two species are newly described from the Bolivian Andes: Lepraria achariana Flakus & Kukwa (major compounds: lecanoric, angardianic/roccellic acids and anthraquinones) and L. neojackii Flakus & Kukwa (major compounds: porphyrilic, angardianic/roccellic, cf. rangiformic acids and anthraquinone). Lepraria impossibilis, L. lecanorica and L. rigidula are reported as new for the Southern Hemisphere, L. alpina, L. aff. caesiella and L. squamatica as new to South America, and other species as new to several countries (Argentina, Bolivia, Brazil, Peru, Uruguay). In addition, two putative, undescribed species are discussed. Chemistry, ecology and general information concerning distribution of the species are presented, and the differentiation of some critical taxa discussed. A provisional key to Lepraria in South America is provided.

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The main aims of this work were to assess phylogenetic relationships of the trentepohlialean photobionts in tropical, mainly sterile, lichens collected in Bolivia, to examine their genetic diversity, host specificity, and the impact of habitat factors on the occurrence of Trentepohliales. Based on rbcL marker analysis, we constructed a phylogenetic tree with eight major clades of Trentepohliales, of which seven free‐living species are intermingled with lichenized ones. Our analyses show that the studied photobionts are scattered across the phylogenetic tree and algae from temperate and tropical regions do not form monophyletic groups, except within one clade that seems to be restricted to the tropics. There is no significant occurrence pattern of lichenized Trentepohliaceae on a specific substratum, except Cephaleuros spp. and Phycopeltis spp., which are restricted to leaves, while some clades with lichenized algae may be specialized to tree bark and wood. Moreover, we found two patterns of associations: first, closely related algae can associate with distantly related mycobionts; second, some other trentepohlioid algae associate with selected lineages of fungi (e.g., Arthoniaceae or Graphidaceae). We also found that some lineages of photobionts are even more selective and associate exclusively with one species (e.g., Dichosporidium nigrocinctum, Diorygma antillarum) or closely related lichen‐forming fungi (Herpothallon spp.). Concluding, we found that occurrence of some trentepohlialean photobionts may correlate with the particular type of the mycobiont.

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.

The present treatment shows that the lichen family Trypetheliaceae is an important component of lowland and montane tropical forests in Bolivia.

ObjectivesThe present study aims to clarify the phylogenetic positions of Cetrariastrum, Everniastrum and Parmelinopsis and also test the hypothesis that the morphological characters have evolved independently within the clade as adaptations to ecological conditions. Material and methodsIn the present study, the generic delimitation in the Hypotrachyna clade is revised using a molecular phylogeny of nuclear ITS, LSU and mitochondrial SSU rDNA sequences of 88 hypotrachynoid taxa. Morphological and chemical features are also revised in each group. Results 118 sequences are newly generated for this study. Our phylogenetic analyses show the polyphyly of Hypotrachyna as currently circumscribed which falls into four wellsupported and one unsupported clade. Cetrariastrum, Everniastrum and Parmelinopsis are nested within Hypotrachyna s. lat., the latter being also polyphyletic and nested in one of the Hypotrachyna clades. Cetrariastrum is monophyletic but clustered within Everniastrum. Two alternative hypotheses tests significantly rejected the monophyly of these three genera. Conclusions As a consequence, the genera Cetrariastrum, Everniastrum, and Parmelinopsis are reduced to synonymy with Hypotrachyna. Further, we here propose an alternative classification to recognize the well--supported clades at subgeneric level and leave the remaining species unclassified within the genus. Five new subgenera are proposed: Hypotrachyna subgen. Cetrariastrum, Hypotrachyna subgen. Everniastrum, Hypotrachyna subgen. Longiloba, Hypotrachyna subgen. Parmelinopsis, and Hypotrachyna subgen. Sinuosa. Forty nine new combinations are proposed.

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