John A. Elix

A molecular phylogeny and a new classification of parmelioid lichens containing Xanthoparmelia -type lichenan (Ascomycota: Lecanorales)

Generic concepts in the parmelioid lichens have been discussed intensively over the past three decades without reaching a broad consensus. We have now employed molecular data from three genes to provide a basis for a revised generic concept of the parmelioid lichens containing Xanthoparmelia-type lichenan. The phylogeny of the parmelioid lichens containing Xanthoparmelia-type lichenan was reconstructed using a combined Bayesian analysis of nuclear ITS, LSU rDNA and mitochondrial SSU rDNA sequences, and a maximum parsimony analysis was also made for comparison. 179 new partial sequences of 58 taxa were generated and 12 sequences were downloaded from GenBank. Our results indicate that the lichens containing Xanthoparmelia-type lichenan form a monophyletic group. However, the segregates proposed earlier do not form distinct clades within the group. Alternative hypotheses of monophyletic Karoowia and Neofuscelia that are not nested within Xanthoparmelia were rejected with our dataset; Karoowia is polyphyletic, and Neofuscelia is reduced to synonymy under Xanthoparmelia. Xanthomaculina convoluta also belongs to Xanthoparmelia. Since we were unable to sequence the umbilicate type species ofXanthomaculina, we refrain from synonymizing that genus with Xanthoparmelia here. The synonymy of Chondropsis and Paraparmelia under Xanthoparmelia already proposed is supported. The revised and enlarged genus Xanthoparmelia includes species that have cell walls with Xanthoparmelia-type lichenan, a palisade plectenchyma with a pored epicortex, lack pseudocyphellae, with usually simple rhizines, generally bifusiform conidia, and medullary chemical diversity. Ten new names are proposed, and 129 new combinations are made into Xanthoparmelia.

THE OCCURRENCE OF COPPER—NORSTICTIC ACID IN LICHENS FROM CUPRIFEROUS SUBSTRATA

The localization of psoromic acid and copper in partly green, copper-rich specimens of Lecidella bullata and Tephromela testaceoatra collected in Norway was studied by optical microscopy, scanning electron microscopy, and electron probe microanalysis. Infrared absorption spectroscopy of lichen material and of a synthetic copper-psoromic acid complex, and the other techniques, provide evidence that complexing of copper by psoromic acid occurs within specific areas of these lichens and this leads to their unusual colouration. In contrast, a specimen of copper-rich Lecanora cascadensis , which contains psoromic and usnic acids, does not contain such a complex. From the evidence obtained it is suggested that taxonomists should pay attention to the impact of rock and lichen chemistry on the appearance of lichen thalli.

Preparation of methoxyphenols by baeyer–villiger oxidation of methoxybenzaldehydes

Baeyer–Villiger oxidation of methoxybenzaldehydes with m-chloroperbenzoic acid in boiling dichloromethane, followed by hydrolysis of the resultant formates, is shown to be a convenient method for the preparation of methoxyphenols.

Evolution of complex symbiotic relationships in a morphologically derived family of lichen-forming fungi.

We 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 protein-coding 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.

Recent Progress in the Chemistry of Lichen Substances

Since the last major review of the chemistry of liehen substances by Huneck in 1971 (171) there has been an accelerating rate of development in this field. As with all areas of natural produet chemistry this impetus has been provided by more rapid and improved methods for detecting, isolating and purifying lichen metabolites and in the structural elucidation of these Compounds. The techniques of thin layer chromatography and high Performance liquid chromatography have provided rapid and efficient methods for the detection and purification of lichen substances and the development of 13C-n.m.r. spectroscopy and sophisticated techniques in 1H-n.m.r. spectroscopy have greatly aided structural studies.

Transoceanic Dispersal and Subsequent Diversification on Separate Continents Shaped Diversity of the Xanthoparmelia pulla Group (Ascomycota)

In traditional morphology-based concepts many species of lichenized fungi have world-wide distributions. Molecular data have revolutionized the species delimitation in lichens and have demonstrated that we underestimated the diversity of these organisms. The aim of this study is to explore the phylogeography and the evolutionary patterns of the Xanthoparmelia pulla group, a widespread group of one of largest genera of macrolichens. We used a dated phylogeny based on nuITS and nuLSU rDNA sequences and performed an ancestral range reconstruction to understand the processes and explain their current distribution, dating the divergence of the major lineages in the group. An inferred age of radiation of parmelioid lichens and the age of a Parmelia fossil were used as the calibration points for the phylogeny. The results show that many species of the X. pulla group as currently delimited are polyphyletic and five major lineages correlate with their geographical distribution and the biosynthetic pathways of secondary metabolites. South Africa is the area where the X. pulla group radiated during the Miocene times, and currently is the region with the highest genetic, morphological and chemical diversity. From this center of radiation the different lineages migrated by long-distance dispersal to others areas, where secondary radiations developed. The ancestral range reconstruction also detected that a secondary lineage migrated from Australia to South America via long-distance dispersal and subsequent continental radiation.

Phylogeny of the cetrarioid core (Parmeliaceae) based on five genetic markers

Fourteen genera belong to a monophyletic core of cetrarioid lichens, Ahtiana, Allocetraria, Arctocetraria, Cetraria, Cetrariella, Cetreliopsis, Flavocetraria, Kaernefeltia, Masonhalea, Nephromopsis, Tuckermanella, Tuckermannopsis, Usnocetraria and Vulpicida. A total of 71 samples representing 65 species (of 90 worldwide) and all type species of the genera are included in phylogentic analyses based on a complete ITS matrix and incomplete sets of group I intron, β-tubulin, GAPDH and mtSSU sequences. Eleven of the species included in the study are analysed phylogenetically for the first time, and of the 178 sequences, 67 are newly constructed. Two phylogenetic trees, one based solely on the complete ITS-matrix and a second based on total information, are similar, but not entirely identical. About half of the species are gathered in a strongly supported clade composed of the genera Allocetraria, Cetraria s. str., Cetrariella and Vulpicida. Arctocetraria, Cetreliopsis, Kaernefeltia and Tuckermanella are monophyletic genera, whereas Cetraria, Flavocetraria and Tuckermannopsis are polyphyletic. The taxonomy in current use is compared with the phylogenetic results, and future, probable or potential adjustments to the phylogeny are discussed. The single non-DNA character with a strong correlation to phylogeny based on DNA-sequences is conidial shape. The secondary chemistry of the poorly known species Cetraria annae is analyzed for the first time; the cortex contains usnic acid and atranorin, whereas isonephrosterinic, nephrosterinic, lichesterinic, protolichesterinic and squamatic acids occur in the medulla. Notes on the anatomy of Cetraria annae and Flavocetraria minuscula are also provided.

Secondary Chemistry of Lichen-forming Fungi: Chemosyndromic Variation and DNA-analyses of Cultures and Chemotypes in the Ramalina farinacea Complex

Abstract The Ramalina farinacea (L.) Ach. complex has a world-wide distribution. The thalli are highly variable both morphologically and chemically, with various β-orcinol depsidones being produced as secondary medullary compounds. In the present study a new, rare chemotype containing cyclographin was detected by HPLC analyses. The aposymbiotically grown mycobionts, isolated from the different chemotypes (containing protocetraric, hypoprotocetraric, norstictic/ salazinic/consalazinic, and cyclographin/virensic acids) exhibited a relatively stable chemical profile in culture; the same or closely related secondary metabolites were biosynthesized under variable culture conditions. In one case, exposure of the culture to a particular set of growth parameters repeatedly led to the production of cyclographin as a major compound. The metabolites present in the Ramalina farinacea complex could be classified as an extended chemosyndrome of biochemically and biosynthetically related depsidones. The new chemotype also differs in morphology, exhibiting a long stranded growth form rather than the more tufted thallus typical of the protocetraric acid chemotype. A molecular phylogenetic analysis of Ramalina, including the most common and the rarest chemotype (the protocetraric acid and cyclographin/virensic acid chemotypes, respectively), suggested monophyly of this species, and its placement in a clade of chemically diverse Ramalina species.

A Revision of the Usnic Acid Containing Taxa Belonging to Lecanora sensu stricto (Lecanorales: Lichenized Ascomycotina)

Eighteen taxa belonging to the Lecanora subfusca group that contain usnic acid in addition to atranorin are revised on a worldwide basis. The following species are described as new: L. alba Lumbsch from Australia, L. floridula Lumbsch from Florida, L. formosula Lumbsch from Australasia, L. neonashii Lumbsch from Mexico, and L. transvaalensis Lumbsch from South Africa. A xanthone containing population of L. wilsonii is distinguished as L. wilsonii ssp. xanthophora Lumbsch. Lecanora achroella and L. subflavicans are reduced to synonymy with L. achroa, and L. elatinoides var. straminea with L. elatinoides. A key to the taxa treated is included. After consid- eration of the morphological, anatomical, and chemical variation, it is concluded that the usnic acid containing species of Lecanora do not form a natural group and cannot be separated from

The Joint Occurrence of Chloroxanthones in Lichens, and a Further Thirteen New Lichen Xanthones

The following new xanthones are shown to co-occur in various combinations with other known naturally occurring xanthones: 2-chloronorlichexane (in Lecanora populicola Lecanora sp.), 7-chloronorlichexanthone (in Lecanora populicola, Lecanora sp.), 5-chloro-6-O- methylnorlichex- anthone (in Lecanora contractula), 5-chlorolichexanthone (in Lecanora contractula), 7-chloro-6- 0- methylnorlichexanthone (in Lecanora populicola, L. salina, L. sp.), 2,4-dichloronorlichexanthone (in Lecidella vorax), 2,7-dichloro-3-O-methylnorlichexanthone (in Lecanora behringii, L. salina, L. sp.), 2,7-dichloro-6-O-methylnorlichexanthone (in Lecanora behringii, L. populicola, L. salina, L. sp.), 2,5, 7-trichlorolichexanthone (in Lecanora broccha), 4,5, 7-trichloro-6-O-methylnorlichex- anthone (in Pertusaria pycnothelia var. A), 3-O-methylthiophanic acid (in Lecidella meiococca), and 6-O-methylthiophanic acid (in Micarea isabellina). Griseoxanthone C (3-0-methylnorlichex- anthone) is reported for the first time from a lichen (Lecanora vinetorum). The joint occurrence of these chloroxanthones has been rationalized in biosynthetic terms and represented in a series of pathway diagrams. All were found to constitute coherent arrays of major xanthones and biose- quentially related satellite derivatives. In so doing we have established the methodologyfor predicting expected co-occurrences and completing similar data sets for other xanthone-containing species. The many secondary metabolites found in the lichen-forming fungi continue to play a dominant role in the systematics of these organisms because of the extensive parallels with morphology and their clear ecological significance. Of the varied structural types present, the aromatic polyketides are especial- ly well represented, particularly the depsides, dep- sidones, and dibenzofurans derived biosynthetically from two acetyl-polymalonyl chains (Culberson & Elix 1989; Mosbach 1969). Anthraquinones and xanthones are also common lichen metabolites, but these substances derive from a single polyketide chain and often occur in or are very closely related to products in the nonlichen fungi. Despite their common occurrence in a number of important gen- era, lichen xanthones have not featured prominently in the repertoire of lichen taxonomists for several reasons. Difficulties were experienced in distin- guishing the numerous (and often isomeric) com- pounds involved, a problem compounded by a number of structural misdeterminations in earlier