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The lichen-forming fungal genus Flavoparmeliaincludes species with distinct distribution patterns, including subcosmopolitan, restricted, and disjunct species. We used a dataset of nuclear ITS and LSU ribosomal DNA including 51 specimens to understand the influence of historical events on the current distribution patterns in the genus. We employed Bayesian, maximum likelihood and maximum parsimony approaches for phylogenetic analyses, a likelihood-based approach to ancestral area reconstruction, and a Bayesian approach to estimate divergence times of major lineages within the genus. We identified two major clades in the genus, one of them separating into two subclades and one of those into four groups. Several of the groups and clades have restricted geographical ranges in the Southern Hemisphere, but two groups include species with wider distribution areas. Our analyses suggest that the genus originated in southern South America during the Eocene–Oligocene transition and that the diversification of the Australasian groups occurred recently. The subcosmopolitan distribution of species is explained by long-distance dispersal, while vicariance probably played a major role in the origin of the genus. Several currently accepted species were found to be non-monophyletic, indicating that the species delimitation in the genus requires further studies.

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.

The photosynthetic capacity of lecanorine apothecia, and their relative importance for the CO2balance of the thallus have been evaluated in the fruticose desert lichen Teloschistes lacunosus(RUPR.) SAV. under laboratory conditions. Three kinds of thalli were selected: thalli without apothecia, thalli with few apothecia and thalli with many apothecia. In each set chlorophyll content, net photosynthesis and dark respiration rates were studied. CO2gas exchange of isolated apothecia of Teloschistes lacunosuswas also measured. The lecanorine apothecium proved to have high rates of net photosynthesis and chlorophyll content, comparable to the most active regions of thalli without or with few apothecia. However, chlorophyll content and net photosynthesis rates, (expressed on dry weight basis), of thalli with many apothecia were significantly lower than those of thalli without or with few apothecia. It is discussed whether this difference is due to a structural alteration in the thallus. For this purpose, photobiont distribution and structure of thalli with many apothecia were compared with those of the thalli without or with few apothecia. The laciniae that carry apothecia have a smaller chlorophyll content than laciniae from thalli carrying no or few apothecia. Under laboratory conditions, the lecanorine apothecia of T. lacunosusare shown to be self-sufficient with respect to its CO2balance.