LECANORA BARKMANEANAA NEW NITROPHILOUS SOREDIATE CORTICOLOUS LICHEN FROM THE NETHERLANDS

Lecanora barkmaneana, a sorediate corticolous lichen belonging to theLecanora subfuscagroup, is described as a species new to science on the basis of numerous sterile collections. It is known so far as only from the Netherlands, where it often grows on roadside trees. it seems to be spreading rapidly at nutrient-rich sites.     

The sorediate, saxicolous species of the Lecanora subfusca group in Europe

The sorediate, saxicolous members of the Lecanora subfusca group, which include L. campestris ssp. dolomitica, L. caesiosora, L. pannonica , and L. umbrosa , although frequently misnamed, can be distinguished morphologically and chemically. Lecanora caesiosora is most variable, with a southerly form having a dark grey, thick thallus, and a more northerly, often shade-loving, morphotype having a very pale, thin thallus. The species are described, and a diagnostic key is presented including some confusable species. Lecanora pannonica and L. neglecta are neotypified.     

Two new sorediate species of lichens in the Catillariaceae from the Iberian Peninsula

Abstract:Two new species of lichens are described from the Iberian Peninsula. Halecania giraltiae is the first sorediate saxicolous species known in the genus and has been collected growing on lichens and sometimes directly on rock in localities from northern Portugal to central Spain. Catillaria fungoides, a sorediate, corticolous representative of the C. nigroclavata group, is known from southern Portugal and northern Spain.     

<Emphasis Type="Italic">Lecanora flavoleprosa</Emphasis> (Lecanoraceae,lichenized Ascomycota) found in the Carpathians

The recently described, terricolous and corticolous, sorediate lichen Lecanora flavoleprosa (belonging to the L. symmicta group) is for the first time recorded from the Carpathians. So far, this rare European species has only been reported from a few localities in the Austrian and Swiss Alps, and Fennoscandia (Norway and Sweden). In this paper several records from the Polish and Slovak Tatra Mts are presented, most of them found recently, but a few also discovered during revision of old material collected by Z. Tobolewski. The ecology and chemistry of the taxon, and differences from related sorediate Lecanora species are briefly discussed.     

Two sorediate crustose lichens assigned to Lecanora

Nordin, A., Sundin, R. & Thor, G. 1995. Two sorediate crustose lichens assigned to Lecanora. — Nord. J. Bot. 15: 553–556. Copenhagen. ISSN 0107–055X.
Lecanora viridissima is described and L. navarrensis is reported from Sweden (Dals-land, Sodermanland, Gotland, Oland, Smiland) and Estonia (Laanema, Saarema). The latter species is reported with apothecia from one locality in Sweden. Lecanora viridissima has not been found with apothecia or pycnidia but is placed in Lecanora due to its general habit and the presence of atranorin. It is distinguished by its morphology, chemistry and habitat. Lecanora viridissima has so far only been found on the island of Gotland in Sweden.     

Biatora britannica sp. nov. and the occurrence of Biatora efflorescens in the British Isles

Abstract:Biatora britannica sp. nov. is described from Wales. The species is the sorediate sister taxon of the Madeiran Biatora hertelii. The close relationship is supported by the presence of the hymenial pigment Hertelii-green, which is hitherto known only from these two species. Molecular data from the nuclear ITS-region of 14 Biatora -species renders further support for the close relationship of both species. Sterile, sorediate material from the British Isles earlier referred to B. efflorescens may in fact belong to B. britannica.     

New species or interesting records of foliicolous lichens. VIII. Two new taxa from tropical Africa,with a key to sorediate Fellhanera species

Abstract:Two new species belonging to the lichen families Pilocarpaceae andEctolechiaceae are described from tropical Africa: Calopadia lucida sp. nov. (Ectolechiaceae) from Tanzania, being similar to C. puiggarii but differing in the UV fluorescent thallus and the pruinose apothecia, andFellhanera ivoriensis sp. nov. (Pilocarpaceae) from the Ivory Coast, differing from the related F. rhapidophylli by the sorediate thallus and from other sorediate taxa by the combination of pale soralia, dark brown apothecia, and the ellipsoid-bacillar conidia. A key to the nine sorediate species of Fellhanera is provided.     

PHOTOBIONT INVENTORY OF A LICHEN COMMUNITY GROWING ON HEAVY-METAL-RICH ROCK

Abstract: The photobiont inventory of a stand of the Acarosporetum sinopicae, a lichen community comprising saxicolous, chalcophilous lichens, has been analysed. Investigated lichen species were Acarospora rugulosa, A. sinopica, Bellemerea diamartha, Lecanora polytropa, L. subaurea, Lecidea silacea, L. lapicida, Rhizocarpon geographicum, and Umbilicaria cylindrica. For all these lichen species this is the first record of the photobionts, except for L. lapicida. The photobionts were cultured axenically and investigated using light microscopical and molecular methods (ITS-sequence analyses). Every lichen species contained only one photobiont species. All photobionts belong toTrebouxia jamesii , but two different subspecies were found with the morphological differences corresponding to molecular differences. The new subspecies T. jamesii subsp. angustilobata is described, differing from the typical T. jamesii by a crenulate chloroplast but identical to the latter taxon in respect to the pyrenoid structure in the light microscope. These results are discussed with respect to the photobiont inventory of the Physcietum adscendentis, analysed in an earlier study.     

Small increase in substratum [corrected] pH causes the dieback of one of Europe's most common lichens, Lecanora conizaeoides

Backgrounds and Aims

Lecanora conizaeoides was until recently western and central Europe''s most abundant epiphytic lichen species or at least one of the most common epiphytes. The species is adapted to very acidic conditions at pH values around 3 and high concentrations of SO₂ and its derivatives formed in aqueous solution, and thus spread with increasing SO₂ deposition during the 19th and 20th centuries. With the recent decrease of SO₂ emissions to nearly pre-industrial levels within 20 years, L. conizaeoides declined from most of its former range. If still present, the species is no longer the dominant epiphyte, but is occurring in small densities only. The rapid spread of the L. conizaeoides in Europe from an extremely rare species to the probably most frequent epiphytic lichen and the subsequent rapid dieback are unprecedented by any other organism. The present study aimed at identifying the magnitude of deacidification needed to cause the dieback of the lichen.

Methods

The epiphytic lichen diversity and bark chemistry of montane spruce forests in the Harz Mountains, northern Germany, were studied and the results were compared with data recorded with the same methods 13–15 years ago.

Key Results

Lecanora conizaeoides, which was the dominant epiphyte of the study area until 15 years ago, is still found on most trees, but only with small cover values of ≤1 %. The bark pH increased by only 0·4 pH units.

Conclusions

The data suggest that only slight deacidification of the substratum causes the breakdown of the L. conizaeoides populations. Neither competitors nor parasites of L. conizaeoides that may have profited from reduced SO₂ concentrations are likely causes of the rapid dieback of the species.     

MOLECULAR SYSTEMATICS OFLECANORASUBGENUSPLACODIUM

A first hypothesis for the phylogeny ofLecanorasubgen.Placodiumis presented by using molecular data. Previous evolutionary ideas and classification concepts for this group with non-molecular data are re-investigated using DNA sequence data from the nuclear ITS and 5.8S regions. UsingProtoparmeliaas an outgroup, theLecanora subfuscagroup together with theL. rupicolagroup appear as a sister group to assemblages with lobate species. Subgen.Placodium, as currently accepted, is not monophyletic. Molecular data suggest that theLecanora dispersagroup and theL. polytropagroup are widened by lobate species and there is evidence from the ITS data that the monotypic genusArctopeltisPoelt is closely related to theL. dispersagroup. A congruence between molecular data and secondary chemistry supports the broader concept of theL. dispersagroup suggested by the molecular data.     

TWO NEW SOREDIATE TAXA OFPELTIGERA

Examination of specimens ofPeltigera didactyla, from Africa, Asia, Europe and North America revealed that this sorediate species includes three entities that can be separated on morphological characters. A new species,P. lambinonii, is described from East Africa, and a new combinationP. didactylavar.extenuata, is proposed to accommodate morphs from mesic forest habitats in Asia, Europe and North America. Despite this taxonomic reduction,P. didactylavar.didactylaremains a ubiquitous taxon. The former two taxa often produce methyl gyrophorate, which can co-occur with traces of gyrophoric acid. These tridepsides were only rarely detected in var.didactyla; their occasional presence seems to be best explained by hybridization. The taxonomic and ecological significance of these substances is discussed.     

Culturable bacteria associated with Antarctic lichens: affiliation and psychrotolerance

Antarctic habitats harbour yet unexplored niches for microbial communities. Among these, lichen symbioses are very long-living and stable microenvironments for bacterial colonization. In this work, we present a first assessment of the culturable fraction of bacteria associated with Antarctic lichens. A phylogenetic analysis based on 16S rRNA gene sequence of 30 bacterial strains isolated from five epilithic lichens belonging to four species (Lecanora fuscobrunnea, Umbilicaria decussata, Usnea antarctica, Xanthoria elegans) shows that these represent the main bacterial lineages Actinobacteria, Firmicutes, Proteobacteria and Deinococcus-Thermus. Within the Actinomycetales, two strains group in the genera Arthrobacter and Knoellia, respectively. Most of the other Actinobacteria form well-supported groups, but could be assigned with certainty only at the family level, and one is in isolated position in the Mycobacteriaceae. The strains in Firmicutes and Proteobacteria belong to the genera Paenibacillus, Bacillus and Pseudomonas, which were already reported from lichen thalli. Some genera such as Burkholderia and Azotobacter, reported in the literature as also associated with lichens, have not been detected in this study. One strain represents the first record of Deinococcus in epilithic lichens; it is related to the species Deinococcus alpinitundrae from Alpine environments and may represent a new species. Further separated and well-supported clades indicate the presence of possibly new entities. Some of the examined strains are related to known psychrophilic bacteria isolated from ice and other extreme environments, others with bacteria distributed worldwide even in temperate climates. Most of the strains tested were able to grow at low temperatures, but tolerated a wider range of temperature. Ecological and evolutionary implications of these lichen-associated bacteria are discussed.     

Caloplaca erodens [sect. Pyrenodesmia], a new lichen species from Italy with an unusual thallus type

Caloplaca erodens is a new species of sect. Pyrenodesmia, characterised by an orbicular, sorediate, bluish-grey thallus which is endolithic but emerges at the periphery with a white, K−, obscurely lobate prothallus. The species is frequent on calcareous outcrops and walls of isolated churches and ruins of the Central Apennines (Sibillini, Gran Sasso), where it may occur in large monospecific populations, from 1000 to 2500 m asl., and is also known from dry sites of the southern Alps. It has been found with apothecia only in the type locality, being predominantly sterile. The reproduction of this lichen is evidently linked to the release of fragments of clusters of photobiont cells and mycobiont hyphae which are continuously exposed with the dissolution of the substratum. Readily distinguished from the apparently similar endolithic C. alociza (which is characterised by numerous apothecia, black, K+ purple prothallus, and esorediate thallus), C. erodens probably belongs to the C. circumalbata complex, whose taxa are always epilithic but have a white, K− prothallus. The phylogenetic position of the new species within sect. Pyrenodesmia as inferred by ITS sequences of the nuclear ribosomal DNA is shortly discussed.     

Micarea viridileprosa sp. nov., an overlooked lichen species from Western Europe

Abstract:A new lichen species, Micarea viridileprosa, is described from western Europe, where it is locally very common. This species, which has previously been much overlooked, is corticolous, lignicolous and terricolous and is usually found sterile. Some specimens of the new species were formerly included in Micarea prasina. The new combination Micarea levicula (Nyl.) Coppins is made for Lecidea levicula Nyl. from Cuba.     

A new isidiate species of Catillaria from the Netherlands

Abstract:A new lichen species, Catillaria nigroisidiata, is described from the Netherlands: it is the first isidiate species known in the genus and has been collected growing on granite on dykes in the north-eastern part of the country. This new species is easily overlooked because of the completely black appearance. A key toCatillaria s.str. in western Europe is provided.     

LECANORA VACILLANSH. MAGN., A REMARKABLE SPECIES AND ITS TAXONOMIC SIGNIFICANCE

The anatomy and chemistry ofLecanora vacillansH. Magn. has been studied. This saxicolous species combines key characters of both theL. subfuscaandL. subcarneagroups and indicates that the representative groups should not be segregated at generic level. More particularlyL. vacillansresembles theL. subfuscagroup in its apothecial anatomy but contains chemical substances typical of theL. subcarneagroup, whereas the morphology is reminiscent of both groups.Lecanora vacillansf.infuscatais reduced to synonymy withL. vacillans.     

Limonium failachicum (Plumbaginaceae) — New and so far the only endemic plant from Kuwait

Limonium failachicum, a new diploid (2n=18) species ofPlumbaginaceae, is described from Arabia. The species is taxonomically related toL. iranicum andL. carnosum. The new taxon is so far the only known endemic species for the State of Kuwait. Ecology and distribution of the new species is briefly discussed.     

Inaccessible Biodiversity on Limestone Cliffs: Aster tianmenshanensis (Asteraceae), a New Critically Endangered Species from China

Aster tianmenshanensis G. J. Zhang & T. G. Gao, a new species of Asteraceae from southern China is described and illustrated based on evidence from morphology, micromorphology and molecular phylogeny. The new species is superficially similar to Aster salwinensis Onno in having rosettes of spatulate leaves and a solitary, terminal capitulum, but it differs by its glabrous leaf margins, unequal disc floret lobes and 1-seriate pappus. The molecular phylogenetic analysis, based on nuclear sequences ITS, ETS and chloroplast sequence trnL-F, showed that the new species was nested within the genus Aster and formed a well supported clade with Aster verticillatus (Reinw.) Brouillet et al. The new species differs from the latter in having unbranched stems, much larger capitula, unequal disc floret lobes, beakless achenes and persistent pappus. In particular, A. tianmenshanensis has very short stigmatic lines, only ca. 0.18 mm long and less than 1/3 of the length of sterile style tip appendages, remarkably different from its congeners. This type of stigmatic line, as far as we know, has not been found in any other species of Aster. The very short stigmatic lines plus the unequal disc floret lobes imply that the new species may have a very specialized pollination system, which may be a consequence of habitat specialization. The new species grows only on the limestone cliffs of Mt. Tianmen, Hunan Province, at the elevation of 1400 m. It could only be accessed when a plank walkway was built across the cliffs for tourists. As it is known only from an area estimated at less than 10 km² and a walkway passes through this location, its habitat could be easily disturbed. This species should best be treated as Critically Endangered based on the International Union for Conservation of Nature Red List Categories and Criteria B2a.     

Temporal dynamics of algal epiphytes on Leathesia marina and Colpomenia sinuosa macrothalli (Phaeophyceae)

This is the first study on the temporal dynamics of the epiphyte communities of Leathesia marina and Colpomenia sinuosa, in terms of richness, diversity and abundance, and their relationships between the hosts and the environmental factors. A total of 31 epiphyte taxa were recorded, with the two hosts sharing 64.5% of the epiphytic species found. The red algal epiphytic group had the highest abundance on both hosts and the diatoms presented the highest species richness. The epiphyte species on L. marina showed a progressive increase in abundance during the warm seasons that was related to the end of the macroscopic life stage of the host. They also showed a greater specific richness on L. marina than on C. sinuosa, but a lower diversity and evenness, and a clear dominance of the species Urospora penicilliformis and Erythrotrichia carnea. Low abundance of epiphytes was found on C. sinuosa, without temporal variation, but high diversity and evenness and without any dominant species. In addition, a clear zonation was observed on this host, where epiphytic abundance decreased on the lateral and upper part of the thallus.     

Linking Seed Photosynthesis and Evolution of the Australian and Mediterranean Seagrass Genus Posidonia

Recent findings have shown that photosynthesis in the skin of the seed of Posidonia oceanica enhances seedling growth. The seagrass genus Posidonia is found only in two distant parts of the world, the Mediterranean Sea and southern Australia. This fact led us to question whether the acquisition of this novel mechanism in the evolution of this seagrass was a pre-adaptation prior to geological isolation of the Mediterranean from Tethys Sea in the Eocene. Photosynthetic activity in seeds of Australian species of Posidonia is still unknown. This study shows oxygen production and respiration rates, and maximum PSII photochemical efficiency (Fv : Fm) in seeds of two Australian Posidonia species (P. australis and P. sinuosa), and compares these with previous results for P. oceanica. Results showed relatively high oxygen production and respiratory rates in all three species but with significant differences among them, suggesting the existence of an adaptive mechanism to compensate for the relatively high oxygen demands of the seeds. In all cases maximal photochemical efficiency of photosystem II rates reached similar values. The existence of photosynthetic activity in the seeds of all three species implicates that it was an ability probably acquired from a common ancestor during the Late Eocene, when this adaptive strategy could have helped Posidonia species to survive in nutrient-poor temperate seas. This study sheds new light on some aspects of the evolution of marine plants and represents an important contribution to global knowledge of the paleogeographic patterns of seagrass distribution.