The phylogeny of the Micarea prasina group was investigated using mitochondrial small subunit ribosomal DNA sequences from 14 taxa representing this group, four other members of the genus Micarea, and Psilolechia lucida as an outgroup. A total of 31 new mtSSU rDNA sequences were generated, including 10 from the M. micrococca complex. Bayesian, maximum parsimony (MP) and maximum likelihood (ML) methods were used to analyse the data. The results show that M. micrococca is not monophyletic and forms three strongly supported lineages: 1) M. micrococca s. str., 2) M. byssacea (Th. Fr.) Czarnota, Guzow-Krzemińska & Coppins comb. nov., and 3) a putative taxon that requires further studies. Micarea viridileprosa is a sister species to M. micrococca s. str. and the recently described M. nowakii is a sister species to M. prasina s. str. The placement of M. tomentosa within the M. prasina group is confirmed. Micarea hedlundii appears to be more closely related to the M. micrococca complex than M. prasina s. str. Descriptions, illustrations, taxonomic remarks, distribution and habitat data for M. micrococca s. str. and M. byssacea are provided. A lectotype for Biatora byssacea Hampe non Zwackh and a neotype for Catillaria prasina β [var.] byssacea are selected.

Degelia cyanoloma (Schaer.) H. H. Blom & L. Lindblom is resurrected from synonymy and elevated from varietal rank to species. The taxon was earlier referred to D. plumbea (Lightf.) P. M. Jørg. & P. James, however, several discontinuous character states distinguish the two species. Degelia cyanoloma is characterized morphologically by having a large thallus that is pale greyish when dry, lobes that are composed of consecutive trough-shaped segments with an upper surface without squamules, no isidia or soredia, and apothecia discs that are dark reddish brown to blackish. Degelia cyanoloma has a euoceanic distribution and is known from western Europe (Norway, France, Great Britain, Ireland, Portugal, Spain). Based on results from studies of morphology, we hypothesize that D. atlantica (Degel.) P. M. Jørg. & P. James is the closest relative of D. cyanoloma among the European species of the genus whereas D. plumbea is closely related to D. ligulata P. M. Jørg. & P. James.

A new lichen species, Waynea giraltiae van den Boom, is described from southern Portugal and Spain. It is characterized by a very fine tomentum on the squamulose thallus, fusiform, 3-septate ascospores, and strongly curved filiform conidia. It is the first species of the genus containing argopsin. The new species is compared with related Waynea species. Waynea cretica is recorded as new to the Iberian Peninsula.

Pertusaria aceroae and Pertusaria calderae from the Canary Islands are described as new to science. A description of each species is given together with notes on their chemistry, distribution, ecology and taxonomy. Related lichen taxa are discussed.

Two new species of Syncesia are described, which differ from all other species of the genus by having more than 3-septate ascospores. Syncesia afromontana is characterized by a byssoid thallus and 7-septate ascospores, and is known only from the type locality in the Nyungwe Forest in Rwanda where it might be endemic. Syncesia madagascariensis is characterized by a crustose thallus and 5-septate ascospores, and is known only from the type locality in a montane forest in central Madagascar.

A new lichen species, Pyrenula darjeelingensis (Pyrenulaceae), is described from the Eastern Himalayan region of India. It is characterized by having 5-septate to submuriform ascospores with papillate apices and the terminal lumina mostly not separated from the exospore by an endospore layer. Six additional species of Pyrenula are reported for the first time from India: P. acutalis R. C. Harris, P. dermatodes (Borrer) Schaer., P. mastophoroides (Nyl.) Zahlbr., P. mucosa (Vain.) R. C. Harris, P. subelliptica (Tuck.) R. C. Harris and P. thelemorpha Tuck.

As part of our ongoing studies of the Graphidaceae in North America, we resolve the status of all taxa traditionally assigned to the genus Graphina that have been reported from the continent north of Mexico. Treatments for the North American members of Acanthothecis, Carbacanthographis, and Diorygma are presented because several species of Graphina have been reassigned to these genera, and our studies of accumulated herbarium materials revealed the existence of several previously unreported and unrecognized species. The following new combinations are made: Acanthothecis leucopepla, A. mosquitensis, A. peplophora, and A. poitaeoides. Carbacanthographis muriformis is described as new to science based on material from Florida. The following taxa are reported from North America for the first time: Acanthothecis poitaeoides,Diorygma junghuhnii, D. reniforme.

Rinodina fuscoisidiata, a muscicolous isidiate species with large isidia and Pachysporaria-type ascospores is described from Venezuela. This species contains an unknown terpene as a major secondary metabolite in addition to traces of atranorin. It is compared with the four known isidiate Rinodina taxa.

Four species of the genus Graphis Adans. are described as new to science, namely G. archeri, G. invisibilis, G. lueckingii and G. paranaensis. These new species were found growing in restinga forest in southern Brazil.

This study of elevation gradients of lichen species richness in Nepal aimed to compare distribution patterns of different life-forms, substratum affinities, photobiont types, and Nepalese endemism. Distribution patterns of lichens were compared with elevational patterns shown by a wide range of taxonomic groups of plants along the Nepalese Himalayan elevational gradient between 200–7400m. We used published data on the elevation records of 525 Nepalese lichen species to interpolate presence between the maximum and minimum recorded elevations, thereby giving estimates of lichen species richness at each 100-m elevational band. The observed patterns were compared with previously published patterns for other taxonomic groups. The total number of lichens as well as the number of endemic species (55 spp.) showed humped relationships with elevation. Their highest richness was observed between 3100–3400 and 4000–4100m, respectively. Almost 33% of the total lichens and 53% of the endemic species occurred above the treeline (>4300m). Non-endemic richness had the same response as the total richness. All growth forms showed a unimodal relationship of richness with elevation, with crustose lichens having a peak at higher elevations (4100–4200m) than fruticose and foliose lichens. Algal and cyanobacterial lichen richness, as well as corticolous lichen richness, all exhibited unimodal patterns, whereas saxicolous and terricolous lichen richness exhibited slightly bimodal relationships with elevation. The highest lichen richness at mid altitudes concurred with the highest diversity of ecological niches in terms of spatial heterogeneity in rainfall, temperature, cloud formation, as well as high phorophyte abundance and diversity implying large variation in bark roughness, moisture retention capacity, and pH. The slightly bimodal distributions of saxicolous and terricolous lichens were depressed at the elevational maximum of corticolous lichens.

Estimating carbon budgets for poikilohydric organisms, such as lichens and bryophytes, requires methods other than those for homoiohydric plants due to a strong dependency of carbon gain on fluctuating hydration. This paper provides guidance with respect to optimal sampling strategies for estimating annual carbon budgets of lichens and bryophytes, based on a one-year dataset of half-hourly CO2-exchange readings on the epilithic placodioid lichen Lecanora muralis (syn. Protoparmeliopsis muralis) and tests the effects of reduced sampling frequencies and different temporal sampling schemes on carbon budget estimates. Both fine-scale sampling (measurements within a day) and large-scale sampling (selection of days within a year) are addressed.

Lowering the sampling frequency within a day caused large deviations for 24-h (diel) budget estimates. Averaged over a larger number of days, these errors did not necessarily cause a large deviation in the annual budget estimate. However, the occurrence of extreme deviations in diel budgets could strongly offset the annual budget estimate. To avoid this problem, frequent sampling (c. every 1·5 hours) is necessary for estimating annual budgets. For estimating diel budgets and patterns a more frequent sampling (every c. 0·5 hours, balancing data resolution and disturbance) is often needed.

Sampling fewer than 365 days in a given year inevitably caused estimates to deviate from the ‘true’ carbon budget, i.e. the annual budget based on half-hourly measurements during 365 days. Accuracy increased with total sample frequency, and blocking days caused larger deviations than sampling randomly or regularly spaced single days. Restricting sampling to only one season led to strongly biased estimates. The sampling effort required for a reliable estimate of the annual carbon balance of lichens based on simple extrapolations of diel carbon budgets is impracticably large. For example, a relatively large sample of 52 random days yielded an estimate within 25% of the true annual budget with only 60% certainty. Supporting approaches are therefore suggested, in particular extrapolating diel budgets using ‘weather response types’, possibly aided by diel activity patterns from chlorophyll fluorescence, or modelling CO2 exchange as a function of climatic conditions.

Although the tripartite terricolous lichen Nephroma arcticum is easily accessible to lichen-feeding gastropods, grazing marks are mainly restricted to localized cephalodia with N-fixing Nostoc. We tested if this gastropod preference for cephalodia can be explained by differences in carbon based secondary compounds (CBSCs) in cyanobacterial versus green-algal tissues. CBSCs were non-destructively removed from air-dry thalli by 100% acetone. Compound deficient and control thallus parts were offered to the slug Arion fuscus and grazing preferences were quantified by area measurements in ArcGIS™. The concentrations of CBSCs (phenarctin, usnic acid, nephroarctin and methyl gyrophorate) in thallus parts with and without cephalodia were quantified with HPLC. Compared to purely green-algal parts, cephalodial parts with adjoining fungal tissues contained less defensive compounds, and were preferred by A. fuscus. The cephalodia themselves do not contain any CBSCs. After acetone rinsing, A. fuscus did not discriminate between green-algal and cyanobacterial parts. The results were consistent with the hypothesis that CBSCs in green-algal parts of N. arcticum play a herbivore-defensive role. It is further hypothesized that grazing of cephalodia may lead to N-starvation and reduced growth of N. arcticum thalli in southern portions of its range where lichenivorous gastropods are more abundant. This may play a role in shaping the southern distribution limit of this arctic-boreal lichen species.