Revisions of British and Irish Lichens is a free-to-access serial publication under the auspices of the British Lichen Society, that charts changes in our understanding of the lichens and lichenicolous fungi of Great Britain and Ireland. Each volume will be devoted to a particular family (or group of families), and will include descriptions, keys, habitat and distribution data for all the species included. The maps are based on information from the BLS Lichen Database, that also includes data from the historical Mapping Scheme and the Lichen Ireland database. The choice of subject for each volume will depend on the extent of changes in classification for the families concerned, and the number of newly recognized species since previous treatments. To date, accounts of lichens from our region have been published in book form. However, the time taken to compile new printed editions of the entire lichen biota of Britain and Ireland is extensive, and many parts are out-of-date even as they are published. Issuing updates as a serial electronic publication means that important changes in understanding of our lichens can be made available with a shorter delay. The accounts may also be compiled at intervals into complete printed accounts, as new editions of the Lichens of Great Britain and Ireland.

Glacial relicts have been regionally morecommon in glacial than in recent times. A rigorousassessment of which species are indeed glacial relictsis extremely difficult because direct evidence is untraceableor equivocal for many species.We aimed to identifyspecies of theWestern Carpathian flora (vascular plants,bryophytes and terrestrial lichens) that display apparentbiogeographical and ecological symptoms, suggesting awider regional or supra-regional distribution during glacialtimes, or at least before the middle-Holoceneclimate optimum. We worked with the premise thatexemplary relict species should tolerate continentaland/or arctic climates, should have large distributionranges with disjunctions, being regionally rare and ecologicallyconservative nowadays, should be associatedwith habitats that occurred during glacial times (tundra,steppe, peatland, open coniferous forest) and shoulddisplay a restriction of ecological niches in the studyregion. The assessed species were primarily those withboreo-continental or artcic-alpine distribution.We demonstrateda conspicuous gradient of glacial-relict symptoms,with Carex vaginata, Betula nana, Trichophorumpumilum, Nephroma arcticum, Saxifraga hirculus andCladonia stellaris topping the ranking. Based on thearbitrary ranking, 289 taxa can be considered highprobabilityrelicts. For only a minority of them, thereare any phylogeographical and/or palaeoecological dataavailable from the study area. Biogeographical and ecologicalsymptoms of 144 taxa suggest that they retreatedrapidly after the Last Glacial Maximum whereas otherspecies probably retreated later. The first principal componentof biogeographical symptoms sorted speciesfrom circumpolar arctic-alpine species of acidicpeatlands and wet tundra to strongly continental speciesof steppe, steppe-tundra and mineral-rich fens. Thisdifferentiation may mirror the altitudinal zonation ofglacial vegetation in the Western Carpathians.

Aims: Classification of  European bog   vegetation (Oxycocco- Sphagnetea class);    iden  -tification of  diagnostic species for   the   class    and   vegetation subgroups (orders and alliances); development of  an  expert     system for   automatic classification of  vegetation plots; and production of distribution maps of the Oxycocco- Sphagnetea class and its alliances.Location: Europe.Methods: A  data   set   of  vegetation- plot   records was   compiled to  include various bog types    over    most    of  the   European continent. An   unsupervised classification (beta- flexible linkage    method, Sørensen distance measure) and  detrended correspondenceanalysis (DCA)    ordination were    applied. Formal definitions of  syntaxa based    on  spe -cies  presence  and  covers,  and  respecting  the  results  of  the  unsupervised  classifica-tion, were developed and included in a classification expert system.Results: The Oxycocco- Sphagnetea class,    its  two   orders (Sphagno- Ericetalia  tetralicisand Sphagnetalia medii)  and   seven    compositionally distinct alliances were    formally de -fined.    In  addition to  the   syntaxa included in  EuroVegChecklist, three    new    alliances were distinguished: Rubo chamaemori- Dicranion elongati (subarctic polygon and   palsa mires);    Erico mackaianae- Sphagnion papillosi (blanket bogs   of  the  northwestern IberianPeninsula); and  Sphagno  baltici- Trichophorion  cespitosi (boreal bog   lawns). The   latter alliance is newly described in this article.Conclusions: This   first   pan-   European formalized classification of  European bog   veg -etation partially followed the   system presented in  EuroVegChecklist, but   suggested three  additional  alliances.  One  covers  palsa  and  polygon  mires,  one  covers  Iberian  bogs    with    endemics and   one   fills   the   syntaxonomical gap   for   lawn    microhabitats in boreal    bogs.    A  classification expert     system has   been   developed, which    allows    assign   -ment of vegetation plots to the types described.

Background

In this study, we investigate species limits in the cyanobacterial lichen genus Rostania (Collemataceae, Peltigerales, Lecanoromycetes). Four molecular markers (mtSSU rDNA, β-tubulin, MCM7, RPB2) were sequenced and analysed with two coalescent-based species delimitation methods: the Generalized Mixed Yule Coalescent model (GMYC) and a Bayesian species delimitation method (BPP) using a multispecies coalescence model (MSC), the latter with or without an a priori defined guide tree.

Results

Species delimitation analyses indicate the presence of eight strongly supported candidate species. Conclusive correlation between morphological/ecological characters and genetic delimitation could be found for six of these. Of the two additional candidate species, one is represented by a single sterile specimen and the other currently lacks morphological or ecological supporting evidence.

Conclusions

We conclude that Rostania includes a minimum of six species: R. ceranisca, R. multipunctata, R. occultata 1, R. occultata 2, R. occultata 3, and R. occultata 4,5,6. Three distinct Nostoc morphotypes occur in Rostania, and there is substantial correlation between these morphotypes and Rostania thallus morphology.

With rare exceptions, the shape and appearance of lichen thalli are determined by thefungal partner; thus, mycobiont identity is normally used for lichen identification. However, it hasrepeatedly been shown in recent decades that phenotypic data often does not correspond with fungalgene evolution. Here, we report such a case in a three-species complex of red-fruited Cladonia lichens,two of which clearly differ morphologically, chemically, ecologically and in distribution range. Weanalysed 64 specimens of C. bellidiflora, C. polydactyla and C. umbricola, mainly collected in Europe,using five variable mycobiont-specific and two photobiont-specific molecular markers. All mycobiontmarkers exhibited very low variability and failed to separate the species. In comparison, photobiontidentity corresponded better with lichen phenotype and separated esorediate C. bellidiflora from thetwo sorediate taxa. These results can be interpreted either as an unusual case of lichen photomorphsor as an example of recent speciation, in which phenotypic differentiation precedes the separation ofthe molecular markers. We hypothesise that association with different photobionts, which is probablyrelated to habitat differentiation, may have triggered speciation in the mycobiont species.