Phylogenetic generic classification of parmelioid lichens (Parmeliaceae, Ascomycota) based on molecular, morphological and chemical evidence

Abstract

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.

Goodbye morphology? A paradigm shift in the delimitation of species in lichenized fungi

“…We are hopeful that lichenologists, who traditionally have been eager to include new methods, such as chromatography, in their routine identifications, will be amenable to include molecular techniques to their routine examination of specimens for identification and classification. Although this may prove difficult to achieve by single individuals, especially civic scientists that traditionally play and important role in lichen taxonomy (Poelt 1992), the increasing number of collaborative projects in lichenology (e.g., Gueidan et al 2009;Crespo et al 2010b;Lumbsch et al 2011) make us optimistic that broad-scale collaborative approaches will facilitate the inclusion of molecular data in lichen research at all levels. This approach is essential to successfully increase our knowledge of the diversity of lichenized fungi on this planet.…”

“…Subsequent studies demonstrated that the Australian clade actually belongs to an unrelated clade of parmelioid lichens that was placed in the new genus Austroparmelina, which accommodates a number of species with a distribution center in Australasia and adjacent areas of the southern Hemisphere (Crespo et al 2010a). This genus was shown to be unrelated to Parmelina but belonging to the Parmotrema clade as sister-group to a clade consisting of the genera Flavoparmelia and Parmotrema, while Parmelina forms the Parmelina clade with species of the genera Bulbothrix, Myelochroa, and Remototrachyna (Crespo et al 2010b). This is a remarkable case highlighting the potential impact of convergent evolution of thallus morphology on species circumscriptions using morphological characters alone.…”

Briancoppinsia, a new coelomycetous genus of Arthoniaceae (Arthoniales) for the lichenicolous Phoma cytospora, with a key to this and similar taxa

“…There are other well-known examples of lichenicolous fungi that appear to have evolved within a clade that otherwise contains mainly or only lichenized species. An example is the lichenicolous genus Nesolechia that grows exclusively on parmelioid lichens and has been shown to belong to the Parmotrema clade (Parmeliaceae) (Crespo et al 2010).…”

Another example of cryptic diversity in lichen-forming fungi: the new species Parmelia mayi (Ascomycota: Parmeliaceae)

“…(Crespo et al 2010). This and others works have revealed the variety of evolutionary lineages sheltering beneath the umbrella of a single species name, thereby allowing us to increase our knowledge of the real biodiversity of lichens, justifying the use of terms like 'species complex' or 'cryptic' or 'semi-cryptic' species.…”