Parmelioid lichens are a diverse and ubiquitous group of foliose lichens. Generic delimitation in parmelioid lichens has been in a state of flux since the late 1960s with the segregation of the large, heterogeneous genus Parmelia into numerous smaller genera. Recent molecular phylogenetic studies have demonstrated that some of these new genera were monophyletic, some were not, and others, previously believed to be unrelated, fell within single monophyletic groups, indicating the need for a revision of the generic delimitations. This study aims to give an overview of current knowledge of the major clades of all parmelioid lichens. For this, we assembled a dataset of 762 specimens, including 31 of 33 currently accepted parmelioid genera (and 63 of 84 accepted genera of Parmeliaceae). We performed maximum likelihood and Bayesian analyses of combined datasets including two, three and four loci. Based on these phylogenies and the correlation of morphological and chemical characters that characterize monophyletic groups, we accept 27 genera within nine main clades. We re‐circumscribe several genera and reduce Parmelaria to synonymy with Parmotrema. Emodomelanelia Divakar & A. Crespo is described as a new genus (type: E. masonii). Nipponoparmelia (Kurok.) K.H. Moon, Y. Ohmura & Kashiw. ex A. Crespo & al. is elevated to generic rank and 15 new combinations are proposed (in the genera Flavoparmelia, Parmotrema, Myelochroa, Melanelixia and Nipponoparmelia). A short discussion of the accepted genera is provided and remaining challenges and areas requiring additional taxon sampling are identified.

No abstract

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.

Parmelia barrenoae is described as new to science in the P. sulcata complex on the basis of morphological and molecular data. The new species is superficially similar to P. sulcata but differs in having simple rhizines whereas the other species of the complex have squarrose rhizines. Nuclear ITS rDNA and partial β-tubulin gene sequences have been used as molecular markers. In the phylogenetic analysis, P. sulcata falls into four well supported clades, one of them corresponds to the morphotype that is described here as a new taxon. Six samples of the new taxon from different locations on the Iberian Peninsula form a strongly supported monophyletic group.

In the last decade, a number of cryptic species have been discovered in lichenized fungi, especially in species with a cosmopolitan or disjunctive distribution. Parmelia saxatilis is one of the most common and widely distributed species. Recent molecular studies have detected two species, P. ernstiae and P. serrana, within P. saxatilis s. lat., suggesting the existence of considerable genetic diversity that may not yet be expressed at the phenotypic level. Due to the complexity in the P. saxatilis s. lat. group, we used this as a model to study the species boundary and identify cryptic lineages. We used Phylogenetic (Bayes, ML and MP) and genetic distance approaches to analyze ITS and β-tubulin sequences. Our results confirm the existence of another cryptic lineage within P. saxatilis s. lat. This lineage is described herein as a new species, P. mayi. It forms an independent, strongly supported, monophyletic lineage, distantly related to the morphologically similar species P. ernstiae, P. saxatilis and P. serrana. Morphologically, it is indistinguishable from P. saxatilis but the new species is separated by molecular, bioclimatic, biogeographic and chemical characters. At present, P. mayi appears to have a restricted distribution in the northern Appalachian mountain territories of North America. It is found in climatic conditions ranging from hemiboreal and orotemperate to cryorotemperate ultrahyperhumid bioclimates.

Disjunct species distributions may result from a combination of geologic events and long-distance dispersal. The foliose lichen species complex Leptogium furfuraceum-L. pseudofurfuraceum has an intercontinental disjunction pattern. Populations of this species complex are found in western North America, southern South America, Africa, and southern Europe. We conducted a phylogenetic study to reconstruct the biogeographic history of this species complex using two ribosomal genes (ITS and LSU) and a protein-coding gene (partial RPB2). Results indicated that the complex comprises four geographically restricted genetic lineages. A sister relationship was found between populations from the same hemispheres, incongruent with previous data derived from morphological characteristics and geographical classification schemes. Incorporating Bayesian ancestral area reconstruction and Bayesian divergence time estimation, we proposed an evolutionary hypothesis for the species complex. The results suggested that processes of biotic expansion via transoceanic dispersal were responsible for the species divergence and distribution patterns observed today. This study also expands the view that cryptic speciation is not a rare phenomenon among fungi and lichens.

The Mediterranean region, comprising the Mediterranean Basin and the Macaronesian Islands, represents a center of diversification for many organisms. The genetic structure and connectivity of mainland and island microbial populations has been poorly explored, in particular in the case of symbiotic fungi. Here we investigated genetic diversity and spatial structure of the obligate outcrossing lichen-forming fungus Parmelina carporrhizans in the Mediterranean region. Using eight microsatellite and mating-type markers we showed that fungal populations are highly diverse but lack spatial structure. This is likely due to high connectivity and long distance dispersal of fungal spores. Consistent with low levels of linkage disequilibrium and lack of clonality, we detected both mating-type idiomorphs in all populations. Furthermore we showed that the Macaronesian Islands are the result of colonization from the Mediterranean Basin. The unidirectional gene flow, though, seemed not to be sufficient to counterbalance the effects of drift, resulting in comparatively allelic poor peripheral populations. Our study is the first to shed light on the high connectivity and lack of population structure in natural populations of a strictly sexual lichen fungus. Our data further support the view of the Macaronesian Islands as the end of the colonization road for this symbiotic ascomycete.

Family Collemataceae (Peltigerales, Ascomycota) includes species of cyanolichens with foliose to fruticose or crustose thalli, with simple or septate ascospores. The current classification divides this family into two groups on the basis of ascospore types. The objective of this study was to evaluate the phylogenetic relationships within this family. Combined DNA sequence data from the nuclear large subunit and mitochondrial small subunit ribosomal RNA genes were used to evaluate monophyly of the family and the relationships between the largest genera of this family. The results revealed that this family is not monophyletic. Genera Staurolemma and Physma, currently classified within the Collemataceae, were found nested within the Pannariaceae. The second result of this study confirms that the genera Collema and Leptogium, both part of the Collemataceae s. str., are not monophyletic and that the presence of a thallus cortex is not a synapomorphy for Leptogium. The main taxonomic conclusion is that families Collemataceae and Pannariaceae were recircumscribed in light of molecular findings with the latter family now including Staurolemma and Physma. Genera Collema and Leptogium form a single mixed monophyletic group. Inferred ancestral character states within the Collema-Leptogium complex revealed that the ancestor of this family had a thallus without cortex and that a cortex evolved at least twice relatively early in the evolution of the Collemataceae s. str. These independent gains of a thallus cortex seems to be associated with a transition from colonizing bare rocks and soils in semi-arid and exposed habitats to epiphytism in shady humid forests.