bluuebunny/crossref_metadata_2025_split huggingface dataset:
Notes on Xanthoria Th. Fr. II. Xanthoria Poeltii, a New Lichen Species from Europe
Authors: Kondratyuk Sergey , Kärnefelt Ingvar 
Published: September 2002

AbstractXanthoria poeltii, a new species combining characters of X. candelaria and X. ulophyllodes from Sweden, Denmark, Germany and Hungary, is described and illustrated. Comments about its differences from related taxa are provided.
The Lichen Vegetation of Acid Watercourses in England
Authors: Gilbert O. L. , Giavarini V. J. 
Published: September 2002

AbstractThe lichen vegetation of forty-five acid watercourses in England is described and related to ecological variables. The zonation scheme adopted for chalk and limestone streams that involves four overlapping bands of lichen vegetation related to length of submergence is also appropriate for this habitat. The flora involves around 90 species, a number of which are rarely recorded specialists. Evidence is presented that substratum chemistry is a more powerful ecological factor than water chemistry. An attempt has been made to relate the lichen flora to homogeneous stream segments from the headwaters down to the alluvial lowlands. An investigation into the effects of water quality showed that both suspended solids (silting) and eutrophication are highly deleterious to the lichen flora; the submerged and fluvial mesic zones are the first to be affected. The zonation across streams in England is compared with those reported from Germany and found to be closely similar.
Vegetative Establishment and Expansion By the Mycobiont of Cladina Subtenuis
Authors: Hammer Samuel 
Published: September 2002

AbstractCladina subtenuis establishes and expands by mechanisms of the thallus mycobiont. Vegetative reproduction occurs through thallus fragmentation, branch ‘ de-differentiation ’, and the extension of the underground prothallus. Establishment hyphae can be considered as any hyphae that provide the mechanism for these modes of clonal thallus extension. They may originate in various parts of the thallus, laterally on branch surfaces, at the growing tips of branches, or from the inner fungal layers of the podetium. The thallus of C. subtenuis is structurally and functionally plastic. Parts of the photosynthetic lichen thallus can transform into nonphotosynthetic fungal aggregations, and non-photosynthetic aggregations may re-establish as a photosynthetic lichen thallus. These activities expand the area occupied by the clone, and potentially increase its photosynthetic surface.
New and interesting Saxicolous species of strigula
Authors: McCarthy P.M. 
Published: September 2002

AbstractThe saxicolous Strigula fractans sp. nov. and S. rupestris sp. now are described from Lord Howe Island, New South Wales, Australia. A new combination, S. decipiens (Malme) P. M. McCarthy, is proposed for Porina decipiens Malme, and a key to the 17 saxicolous species of Strigula is provided.
Dermatocarpon Leptophyllodes and Related Species in the British Isles
Authors: Orange Alan 
Published: September 2002

AbstractThe species of Dermatocarpon occurring in the British Isles are reviewed, with special reference to the hydrophilous species; a number of related species not yet recorded for the British Isles are also briefly treated. Dermatocarpon deminuens and D. leptophyllodes are confirmed as British; the name D. leptophyllum should be deleted from the British list. The name D. melophyllum is shown to be based on discordant elements. A key is provided to the British and Irish species.
Two New Biatora Species from Western Norway and Madeira
Authors: Printzen Christian , Holien Håkon , Etayo Javier 
Published: September 2002

AbstractBiatora hertelii Printzen & Etayo and B. troendelagica Holien & Printzen are described as new to science. Diagnostic characters, systematic affinities, ecology and distribution of both species are briefly discussed. Divaricatic acid is reported for the first time from a species of Biatora
The Lichen Symbiosis—What is so Spectacular about it?
Authors: Honegger Rosmarie 
Published: September 2002

AbstractLichen mycobionts are typical representatives of their fungal classes but differ from non-lichenized taxa by their manifold adaptations to symbiosis with a population of minute photobiont cells. Most interesting are the morphologically complex macrolichens, the fungal partner of which competes for space above ground and contains photobiont cells optimally positioned for gas exchange and illumination. Such thalli are the product of an amazing hyphal polymorphism, with multiple switches between polar and apolar growth and hydrophilic or hydrophobic cell wall surfaces. Hydrophobic sealing of the apoplastic continuum between the partners by means of mycobiont-derived hydrophobic compounds canalizes the fluxes of solutes during the often quite dramatic de- and rehydration processes and keeps the algal layer gas-filled at any level of hydration. The impressive tolerance of drought, heat and cold stress of most lichen-forming fungi and their photobionts is due to a very interesting combination of protective and repair mechanisms at the cellular level, the molecular bases of which remain to be explored. Contemporary experimental lichenology is analysed and strategies are proposed aimed at better integration into mainstream biology.
Oxidative Stress and Ascorbic Acid Contents in Parmotrema Reticulatum and Parmelia Sulcata Thalli
Authors: Caviglia A. M. , Modenesi P. 
Published: September 2002

AbstractParaquat-treatment of Parmotrema reticulatum and high light levels in the habitat of Pamtelia sulcata can cause oxidative stress, which promotes an increase in ascorbic acid contents of thalli. Ascorbic acid was measured by an HPLC method. In P. reticulatum the increase was more pronounced in summer than in other seasons. In P. sulcata, thalli growing in sun-exposed habitats showed a higher ascorbic acid content than shade-growingspecimens.
A New Belonia From New Zealand and a Second Record of B. Mediterranea
Authors: Coppins Brain J. , Malcolm William M. 
Published: September 2002

AbstractBelonia pellucida sp. nov. is described from coastal scrubland in North Island, New Zealand. This is the third report of the genus Belonia(Gyalectales) from the Southern Hemisphere. Belonia mediterranea is reported for the second time, from Mallorca.
The Potential of Epiphytic Twig Communities on Quercus Petraea in a Welsh Woodland Site (Tycanol) For Evaluating Environmental Changes
Authors: Wolseley P. A. , Pryor K. V. 
Published: September 2002

AbstractA survey of epiphytic species on annual increments of Quercus petraea twigs in a west Wales woodland has shown that distribution of lichen species and rates of succession are affected by a range of environmental conditions. Lichen communities were recorded for 1–15 years on randomly sampled twigs along marked woodland boundaries affected by a range of climatic and management conditions. Results show that there is a correlation between environmental condition and lichen communities of twigs, and that indicator species can be used to detect trends towards acidification or eutrophication.
Physiological Effect of Lichen Secondary Metabolites on the Lichen Parasite Marchandiomyces Corallinus
Authors: Torzilli A. P. , Mikelson P. A. , Lawrey J. D. 
Published: September 2002

AbstractIt has been suggested that the host specificity exhibited by some lichenicolous fungi depends on their ability to tolerate the secondary chemistry of potential host lichens. For example, the lichen parasite Marchandiomyces corallinus is able to degrade the tissues of the lichen Flavoparmelia baltimorensis irrespective of the presence or absence of endogenous phenolic compounds. In contrast, the degradation of tissues from the lichen Lasallia papulosa is suppressed when endogenous phenolics are not removed. We have investigated the physiological basis of this inhibition in order to understand more about how lichen chemistry infiuences host preference in lichenicolous fungi. Results showed that the secondary compounds from L. papulosa inhibit the overall growth of M. corallimis, but not the catalytic activity of its tissue-degrading polysaccharidases. This effect is different from that shown by another lichen parasite, Nectria parmeliae, where lichen compounds specifically inhibited polysaccharidase activity. Compared with the compounds of L. papulosa, the endogenous phenolics of F. baltimorensis inhibited the growth of M. corallimis substantially less and exhibited little or no inhibition of polysaccharidases. For M. corallimis, host preference appears to be associated with physiological adaptation to the chemistry of F. baltimorensis.
The Distribution, Ecology and Conservational Status of the Lichen Genus Biatora in Central Europe
Authors: Printzen Christian , Palice Zdeněk 
Published: September 2002

AbstractThe genus Biatora is still undercollected in many parts of its distributional range. On the basis of recent collections made by the authors and additional herbarium material not studied previously, more detailed statements on the ecology, distribution and conservational status of Biatora species in Central Europe are possible. Distribution maps are provided for B. fallax, B. mendax, B. ocelliformis, B. rufidula, B. sphaeroidiza, and B. vernalis. Biatora species are almost exclusively non-saxicolous and, in general, prefer humid habitats. Many species are chionophilous and extremely shade-tolerant. Three main distributional patterns can be observed: (sub-)arctic-alpine species, sub-oceanic-montane species, and species of montane coniferous or mixed coniferous forests. Biatora efflorescens, B. flavopunctata and B. subduplex are relatively frequent species and are not threatened. Biatora rufidula and B. vacciniicola must be regarded as extinct in Central Europe. The following species are reported for the first time from the respective countries: B. chrysantha from Romania, B. efflorescens from Romania and Ukraine, B. fallax from Austria and Ukraine, B. mendax from the Czech Republic, B. ocelliformis from Romania, and B. sphaeroidiza from Germany, Austria, the Czech Republic and Romania.
Additions and Corrections to the Foliicolous Lichen Flora of Costa Rica. The Family Gyalectaceae
Authors: Lücking Robert 
Published: September 2002

AbstractThis paper provides a revision of the foliicolous representatives of the Gyalectaceae in Costa Rica. Five species of Coenogonium and 13 of Dimerella are distinguished. Coenogonium interplexum, C. interpositum, C. leprieurii, C. linkii and Dimerella vezdana are ubiquitous as to the choice of their substratum, whereas C. moniliforme and Dimerella lutea are facultatively foliicolous. The remainder are typically foliicolous taxa but may occasionally be found on bark. The following species are for the first time reported as foliicolous from Costa Rica: Coenogonium interplexum, C. interpositum, C. leprieurii, C. moniliforme, Dimerella fallaciosa, D lisowskii, and D. aff. pilifera. Three new species are described: Dimerella isidiifera sp. nov. with disciform isidia, D. subzonatasp. nov. with small, bright yellow, dentate apothecia and a whitish prothallus, and D. siquirrensis sp. nov. with large, orange apothecia and a thin whitish prothallus. A key is presented for neotropical foliicolous Gyalectaceae, and notes on the distribution and ecology of the species are given.
Observations on the Genus Psammina, Including the Description of Two New Algicolous and Lichenicolous Species
Authors: Earland-Bennett P. M. , Hawksworth D. L. 
Published: September 2002

AbstractPsammina inflate Earland-Bennett & D. Hawksw. and P. simplex Earland-Bennett & D. Hawksw. are described as new species from coccoid green algae and crustose or leprose lichens in lowland Britain. Additional records and hosts for P. stipitata are reported, and a key to the four species now known in the British Isles is presented. Psammina simplex is the more strongly pathogenic of the species, eventually destroying its hosts. The discovery of these new sp cies adds weight to the view that the genus is more appropriately regarded as a hyphomycete rather than an acervular coelomycete. The size, shape and septation dimensions of the conidial arms were found to be the most reliable characters for specie separations in the genus. Pycnopsammina lobariae Diederich & Etayo is also cited from the British Isles for the first time.
Pcr Optimization and Troubleshooting, with Special Reference to the Amplification of Ribosomal DNA in Lichenized Fungi
Authors: Ekman Stefan 
Published: September 2002

AbstractFactors affecting the outcome of a PCR is discussed. Nested PCR is described and a protocol that has been shown to work well for the amplification of ribosomal genes in ascomycetes is described. It is claimed that DNA extracts of lichenized fungi, contrary to many other organism groups, are often contaminated by other fungi. This poses a problem due to the preferential amplification of short intron-lacking sequences over longer, intron-containing ones, particularly when extension time is limited. A simple protocol for optimizing and troubleshooting PCRs is presented.
Antimicrobial, Antiviral and Cytotoxic Activity of New Zealand Lichens
Authors: Perry Nigel B. , Benn Michael H. , Brennan Nerida J. , Burgess Elaine J. , Ellis Gill , Galloway David J. , Lorimer Stephen D. , Tangney Raymond S. 
Published: September 2002

AbstractA total of 69 species of lichens have been collected from various locations around New Zealand. Screening of extracts of these species for antimicrobial, antiviral and cytotoxic activity showed a high proportion with biological activity. Active extracts were generally from species known to contain phenolic compounds. Bioactivity-directed isolation work on Cladia retipora, Pseudocyphellaria glabra and P. homoeophylla led to the identification of usnic acid as the main antimicrobial, cytotoxic and antiviral component in these three species.
Three New Species in the Lichen Genus Degelia
Authors: Jørgensen P. M , Kantvilas G. , Galloway D. J 
Published: September 2002

AbstractThe following new species are described: Degelia calcicola P. M. Jørg. & Kantvilas, a squamulose species from wet calcareous rocks in Tasmania; D. Crustacea P. M. Jørg. & D. J. Galloway, a crustose, corticolous species from northern New Zealand; and D. subcrustata P. M. Jørg. & Kantvilas from dry granitic rocks in southern Australia and Tasmania.
Studies on the Lichen Family Thelotremataceae in Tasmania. The Genus Chroodiscus and its Relatives
Authors: Kantvilas Gintaras , Vězda Antonín 
Published: September 2002

AbstractThe Tasmanian species of the family Thelotremataceae with thin-walled ascospores and exfoliating, chroodiscoid apothecia are studied in detail. Problems in the delimitation of genera are discussed, and characters such as the morphology of the apothecia, structure and form of the exciple, presence of periphyses, ascus structure, ascospore morphology and thallus chemistry are evaluated. The concept of the typically foliicolous genus Chroodiscus (Müll. Arg.) Müll. Arg. is expanded to include corticolous and terricolous species, and the new taxa C. asteliae Kantvilas & Vězda, C. australis Kantvilas & Vězda, C. australis subsp. tasmanicus Kantvilas & Vězda, C. lamelliferus Kantvilas & Vězda and C. minor Kantvilas & Vězda are described and illustrated. The related Australasian species, C. megalophthalmus (Müll. Arg.) Vězda & Kantvilas is also treated. Two new genera are also described. Pseudoramonia Kantvilas & Vězda, based on the Venezuelan species, P. stipitata (Vězda & Hertel) Kantvilas & Vězda, is introduced to accommodate P. richeae Kantvilas & Vězda; Topeliopsis Kantvilas & Vězda is described to include the Tasmanian taxa, T. muscicola Kantvilas & Vězda and T. rugosa Kantvilas & Vězda, and the North American species T. toensbergii Vězda & Kantvilas.
Calcium Oxalate and Medullary Architecture in Xanthomaculina Convoluta
Authors: Modenesi Paolo , Piana Massimo , Giordani Paolo , Tafanelli Alessandra , Bartoli Antonella 
Published: September 2002

AbstractThe anatomy of Xanthomaculna convolute shows adaptation to a vagrant life form and to the moisture conditions of its habitat. The differential swelling of the irregularly thickened upper cortex and the medulla, in addition to the rigid medullary structure, due to the deposition of calcium oxalate, allow orderly hygroscopic thalline movements. The architecture of the medulla appears to be closely related to masonry-like arches where the material is only stressed by compression and the stresses are distributed at the hinges. The possible role of crystalline medullary deposition as a radiation reflector is also suggested.
Measurement of Age and Growth Rate in the Crustose Saxicolous Lichen Caloplaca Trachyphylla Using 14C Accelerator Mass Spectrometry
Authors: Clark B. M. , Mangelson N. F. , Clair L. L. St. , Rees L. B. , Bench G. S. , Southon¶ J. R. 
Published: September 2002

AbstractSections of the crustose saxicolous lichen, Caloplaca trachyphylla, were dated using 14C accelerator mass spectrometry (AMS). The data show a stron linear dependence of radial position on time (r=0.993), suggesting a constant radial growth rate. This specimen had averaged a marginal growth rate of 1.48 mm/year. Extrapolation of the growth curve yields a thallus age of 20 years. These data demonstrate the feasibility of using AMS technology to precisely date lichen tissues and determine growth rates of lichen thalli.
Biomass of Arboreal Lichens and its Vertical Distribution in a Boreal Coniferous Forest in Central Finland
Authors: Liu Chunjiang , Ilvesniemi Hannu , Westman Car J. 
Published: September 2002

AbstractThe biomass of lichens and its vertical distribution on trees were investigated in a > 100-year-old boreal forest in central Finland. The lichen biomass on individual trees was 1292–3669 g tree−1 on Picea abies and 742 g tree −1 on Pinus sylvestris. More than half of the biomass occurred on dead branches. The proportion of Hypogymnia physodes appeared to rise with the canopy height while the other lichens (Platismatia glauca, Bryoria spp. and Pseudevernia furfuracea) decreased. Mean total lichen biomass for sampled trees on an aerial basis was 163 gm −2. The standing crop of litter lichen deposited on ground was about9 gm −2.
Lecanora Herteliana (Lecanoraceae, Ascomycetes), a New Lichen Species from Spain
Authors: Calatayud Vicent , Barreno Eva 
Published: September 2002

AbstractLecanora herteliana is described from several collections from hard siliceous sandstone, in typically Mediterranean habitats in eastern Spain. The new species has a whitish thallus containing atranorin and norstictic acid. Its apothecia are mostly black, with a thalline exciple, which is finally excluded, and with a well developed true exciple.Lecanora herteliana is most closely related to L. subcoarctata, and it is discussed in relation to this species and other members of the L. marginata group.
Identification of Photobionts from the lichen family Physciaceae using algal-specific ITS rDNA sequencing
Authors: Helms Gert , Friedl Thomas , Rambold Gerhard , Mayrhofer Helmut 
Published: September 2002

AbstractThe identity of photobionts from 20 species of the Physciaceae from different habitats and geographical regions has been determined by ITS rDNA sequence comparisons in order to estimate the diversity of photobionts within that lichen group, to detect patterns of specificity of mycobionts towards their photobionts and as a part of an ongoing study to investigate possible parallel cladogenesis of both symbionts. Algal-specific PCR primers have been used to determine the ITS rDNA sequences from DNA extractions of dried lichens that were up to 5 years old. Direct comparisons and phylogenetic analyses allowed the assignment of Physciaceae photobionts to four distinct clades in the photobiont ITS rDNA phylogeny. The results indicate a diversity within the genus Trebouxia Puymaly and Physciaceae photobionts that is higher than expected on the basis morphology alone. Physciaceae photobionts belonged to 12 different ITS lineages of which nine could unambiguously be assigned to six morphospecies of Trebouxia. The identity of the remaining three sequences was not clarified; they may represent new species. Specificity at the generic level was low as a whole range of photobiont species were found within a genus of Physciaceae and different ranges were detected. The photobionts of Physcia (Schreb.) Michaux were closely related and represented one morphospecies of Trebouxia, whereas the algal partners of Buellia De Not and Rinodina (Ach.) Gray were in distant lineages of the ITS phylogeny and from several Trebouxia morphospecies. Photobiont variation within a genus of Physciaceae may be due to phylogeny, geographical distance or because photobionts from neighbouring lichens were taken (“algal sharing“). At the species level Physciaceae mycobionts seem to be rather selective and contained photobionts that were very closely related within one morphospecies of Trebouxia.
Evolutionary Trends in the Physciaceae
Authors: Scheidegger C. , Mayrhofer H. , Moberg R. , Tehler A. 
Published: September 2002

AbstractThe current delimitation of the family Physciaceae has been generally accepted since detailed descriptions of ascus characters allowed for a more natural circumscription of lichenized ascomycetes. The generic relations within the family are, however, still controversial and depend on the importance different authors attribute to specific morphological or chemical characteristics. The aim of this paper is to describe ascospore ontogeny and to test the present taxonomic structure of the family against a parsimony-based cladistic analysis, which includes three different scenarios of a priori character weighting. A study of ascospore ontogeny revealed two distinct developmental lines. One line revealed a delayed septum formation, which clearly showed transitions from spores with apical and median thickenings to spores without apical, but still well developed median thickenings, and to spores without any thickenings. In the second developmental line with an early septum formation again taxa with no thickenings, median thickenings, and both median and apical thickenings were found. Although these characters were constant at a species level, median wall thickenings especially varied among otherwise closely related taxa. In the cladistic analyses the current taxonomic structure of the Physciaceae was only obtained after the five character groups, namely morphology and anatomy of the vegetative thallus, conidiomata and conidia, morphology and anatomy of the apothecia, ontogeny of the ascospores, and secondary metabolites of the thallus, were given equal importance, and after a subjective a priori weighting further increased the weight of the three characters ‘conidial shape’, ‘presence of apical thickenings’, and ‘spore septation delayed’. This structure was not supported by a cladistic analysis with equally weighted characters but reflected the biased character weighting of the present day Physdaceae taxonomy. The taxonomic importance of conidial characters and of anatomical and ontogenetical spore characteristics need, therefore, a careful reconsideration in future.
Amphorothecium, a new pyrenocarpous lichen genus from New South Wales, Australia
Authors: McCarthy P. M. , Kantvilas G. , Elix J. A. 
Published: September 2002

AbstractAmphorothecium occultum P. M. McCarthy, Kantvilas & Elix gen. et sp. nov. is described from deeply shaded, saxicolous bryophytes in south-eastern New South Wales, Australia. This genus is characterized by a trentepohlioid photobiont, distinctive thallus chemistry, pale, simple perithecia, largely unbranched paraphyses and periphyses, thin-walled, non-amyloid asci and very large, multiseptate ascospores. Its systematic position is uncertain.