Muellerella, a lichenicolous fungal genus recovered as polyphyletic within Chaetothyriomycetidae (Eurotiomycetes, Ascomycota)

Molecular data and culture-dependent methods have helped to uncover the phylogenetic relationships of numerous species of lichenicolous fungi, a specialized group of taxa that inhabit lichens and have developed diverse degrees of specificity and parasitic behaviors. The majority of lichenicolous fungal taxa are known in either their anamorphic or teleomorphic states, although their anamorph-teleomorph relationships have been resolved in only a few cases. The pycnidium-forming Lichenodiplis lecanorae and the perithecioid taxa Muellerella atricola and M. lichenicola were recently recovered as monophyletic in Chaetothyriales (Eurotiomycetes). Both genera are lichenicolous on multiple lichen hosts, upon which they show a subtle morphological diversity reflected in the description of 14 species in Muellerella (of which 12 are lichenicolous) and 12 in Lichenodiplis. Here we focus on the teleomorphic genus Muellerella and investigate its monophyly by expanding the taxon sampling to other species occurring on diverse lichen hosts. We generated molecular data for two nuclear and one mitochondrial loci (28S, 18S and 16S) from environmental samples. The present multilocus phylogeny confirms the monophyletic lineage of the teleomorphic M. atricola and M. lichenicola with their L. lecanorae-like anamorphs, but places the rest of the Muellerella species studied in two different monophyletic lineages with strong support. The first, Muellerella spp. 1, is nested within some new lineages of black fungi isolated from different epilithic lichen thalli, while the second, Muellerella spp. 2, is closely related to the Verrucariales. Based on these results, we reappraise the phylogenetic placement of Muellerella and suggest its polyphyly within Chaetothyriomycetidae.

A first synopsis of lichenicolous fungi of Mongolia, with the description of five new species

A first synopsis of lichenicolous fungi of Mongolia based on new collections and literature data is provided, including 114 species. Five new species are described: Capronia cogtii (on Vahliella leucophaea), Echinothecium hypogymniae (on Hypogymnia bitteri), Feltgeniomyces mongolicus (on H. bitteri), Phacopsis vulpicidae (on Vulpicida juniperina) and Roselliniella javkhlanae (on Rinodina turfacea var. ecrustacea). Two new combinations are proposed: Endococcus hafellneri (≡ Stigmidium hafellneri) and Sphaerellothecium taimyricum (≡ Sphaerellothecium thamnoliae var. taimyricum). Unidentified specimens of Acremonium (on Mycoblastus sanguinarioides), Cercidospora (on Rhizoplaca chrysoleuca s.lat.), Didymocyrtis (on Rhizoplaca chrysoleuca s.lat.), Lichenochora (on Physcia alnophila), Lichenostigma (on species of Xanthoparmelia), Phoma (on Vulpicida juniperina) and a leotialean fungus (on Cetraria laevigata) are characterized and discussed. Taxonomic notes are provided for Cercidospora macrospora s.lat., Didymocyrtis cf. melanelixiae, Minutoexcipula cf. beaglei, Nesolechia cetrariicola, Sphaerellothecium cf. parmeliae and Stigmidium cf. psorae. Sphaeropezia intermedia is newly reported for Eurasia. Didymocyrtis grumantiana is newly reported for Asia. Additionally, 71 species of lichenicolous fungi and five species of lichenicolous lichens are documented in Mongolia for the first time. Allocetraria is reported as a new host genus for Abrothallus peyritschii, Vulpicida for Arthonia triebeliae, and Anamylopsora for Muellerella pygmaea.

Lichenicolous fungi from Florida growing on Graphidales

The lichenicolous fungi growing on Graphidales hosts in Florida are revised, mainly based on collections by the second author (R. C.). Twenty-one species are recognized. The new genus and species Lawreya glyphidiphila is described for a common asexual fungus growing on Glyphis scyphulifera and more rarely Trypethelium eluteriae, characterized by black stromatic conidiomata in which subspherical conidiogenous loculi develop, producing aseptate, subglobose, brown conidia. Nine additional new species are described: Amerosporiopsis phaeographidis (on Phaeographis brasiliensis), Arthonia acanthotheciicola (on Acanthothecis floridensis), A. subgraphidicola (on Graphis assimilis), Hemigrapha graphidicola (on G. assimilis), Skyttea graphidicola (on Graphis spp.), Strigula graphidicola (on G. assimilis), S. perparvula (on Graphidales), Talpapellis graphidis (on Graphis caesiella) and Tremella wedinii (on Glyphis scyphulifera). Phylogenetic placements of Lawreya glyphidiphila, Skyttea graphidicola and Tremella wedinii are presented. Identification keys are given for the species of Cornutispora and Talpapellis, and for the 66 species known to grow on Graphidales hosts worldwide.

Differential responses to salt concentrations of lichen photobiont strains isolated from lichens occurring in different littoral zones

An interesting biota of lichen-forming fungi occurs along rocky seashores of cold and warm-temperate regions in both hemispheres. Most of the species belong to the family Verrucariaceae and form symbioses with an extraordinarily diverse group of photobionts. We isolated the photobionts of three species: Hydropunctaria maura and H. amphibia from the supralittoral zone, and Wahlenbergiella striatula from the upper intertidal zone. We characterized the isolated strains structurally by means of transmission electron microscopy, and molecularly using the nrSSU and nrITS and chloroplast RPL10A regions. Additionally, we studied the response of the strains to different salt concentrations, analyzed the concentration of osmoregulatory solutes, and measured photosynthesis performance by chlorophyll fluorescence and CO2 assimilation techniques. All strains belong to the recently described species Halofilum ramosum, although we found differences in the ITS and RPL10A regions among the strains shared by H. maura and H. amphibia and the strain isolated from W. striatula. Differences were also found in the main osmoregulatory response of the strains growing under high salt concentrations: W. striatula accumulated glycerol, while H. maura and H. amphibia synthetized sucrose. Analyses of photosynthesis performance also indicated differences in physiological behavior between supralittoral-dwelling and intertidal-dwelling species, W. striatula showing lower photosynthetic activity under high irradiance. Our results highlight the role of photobionts in determining lichen zonation on rocky seashores.

The genus Parmotrema (Parmeliaceae, lecanoromycetes) in the Galapagos Islands

As part of an ongoing comprehensive inventory of all Galapagos lichens, the genus Parmotrema has been revised. In Galapagos this genus is represented by thirty-five species, seven described as new to science: Parmotrema cactacearum, P. erectociliatum, P. lawreyi, P. marcellianum, P. pustulotinctum, P. saxoisidiatum and P. weberi. Parmotrema weberi, although previously informally recognized by Mason E. Hale, is now formally described here, the name thus validated. Reports of four species are doubtful or incorrect. Nine species are reported from the Galapagos for the first time, seven of those being also new for Ecuador. Parmotrema cooperi, previously known only from Central America, is now also reported from South America. Detailed descriptions and illustrations are provided for all thirty-five species, together with a dichotomic key for their identification. Diagnostic differences are discussed. If all newly described species are confirmed as endemic to the archipelago, the proportion of endemism within Parmotrema appears to be similar to most other groups of lichens recently reviewed.

Shotgun sequencing decades-old lichen specimens to resolve phylogenomic placement of type material

Natural history collections, including name-bearing type specimens, are an important source of genetic information. These data can be critical for appropriate taxonomic revisions in cases where the phylogenetic position of name-bearing type specimens needs to be identified, including morphologically cryptic lichen-forming fungal species. Here, we use high-throughput metagenomic shotgun sequencing to generate genome-scale data from decades-old (i.e., more than 30 years old) isotype specimens representing three vagrant taxa in the lichen-forming fungal genus Rhizoplaca, including one species and two subspecies. We also use data from high-throughput metagenomic shotgun sequencing to infer the phylogenetic position of an enigmatic collection, originally identified as R. haydenii, that failed to yield genetic data via Sanger sequencing. We were able to construct a 1.64 Mb alignment from over 1200 single-copy nuclear gene regions for the Rhizoplaca specimens. Phylogenomic reconstructions recovered an isotype representing Rhizoplaca haydenii subsp. arbuscula within a clade comprising other specimens identified as Rhizoplaca haydenii subsp. arbuscula, while an isotype of R. idahoensis was recovered within a clade with substantial phylogenetic substructure comprising Rhizoplaca haydenii subsp. haydenii and other specimens. Based on these data and morphological differences, Rhizoplaca haydenii subsp. arbuscula is elevated to specific rank as Rhizoplaca arbuscula. For the enigmatic collection, we were able to assemble the nearly complete nrDNA cistron and over 50 Mb of the mitochondrial genome. Using these data, we identified this specimen as a morphologically deviant form representing Xanthoparmelia aff. subcumberlandia. This study highlights the power of high-throughput metagenomic shotgun sequencing in generating larger and more comprehensive genetic data from taxonomically important herbarium specimens.

A first phylogenetic assessment of Dictyonema s.lat. in southeastern North America reveals three new basidiolichens, described in honor of James D. Lawrey

Three species of lichenized basidiomycetes in the Dictyonema clade from southeastern North America are described as new to science: Cyphellostereum georgianum, C. jamesianum and Dictyonema lawreyi, all with a crustose-filamentous growth form. Based on ITS sequences, the species form well-supported monophyletic clades in a phylogeny and are represented by at least two specimens each. They are also distinguishable by morphological and anatomical characters. These new findings emphasize the importance of lichenological studies in North America, especially in historically understudied taxonomic groups, such as basidiolichens. This study is dedicated to James D. Lawrey on the occasion of his 70th birthday.

Lichen species as element bioindicators for air pollution in the eastern United States of America

Lichen element (N, S, metals) indicators of local air pollution load (a widely used technique) are recommended for five predefined regions covering central and southern parts of the eastern United States. The final recommendations integrate the advice of regional lichenologists, information from regional floras, and species abundance data from a United States Forest Service Forest Inventory and Analysis Program (FIA) lichen database for 11 of the 21 covered eastern states. Recommended species were frequent in their region, easy for nonspecialists to distinguish in the field after training, and easy to handle using clean protocols. Regression models of species abundance in FIA plots from five southeastern states vs. climate, air pollution (both from a regional lichen response model) and type of nearby landcover (from the National Land Cover Database) identified species’ environmental limitations. Punctelia rudecta is recommended for cooler forested uplands of all regions, with three Physcia species combined and Punctelia missouriensis for isolated woodlands or urban areas of three regions. Parmotrema hypotropum and P. hypoleucinum combined (weak environmental limitation) or P. perforatum. and P. subrigidum combined (limited in more polluted areas) are recommended for warmer Coastal Plains in two regions each. Additional species are recommended for single regions. Each species must be quantitatively evaluated in each region, to demonstrate indication reliability in practice and to calculate element data conversions between species for region-wide bioindication.