Thirty-five species of Micarea are recorded for Tasmania. Ten are described as new to science: M. ceracea Coppins & Kantvilas (also known from Victoria and New South Wales), characterized by a thallus containing perlatolic and didymic acids, pallid apothecia and 3(–4)-septate ascospores, 10–21 × 3·5–6 µm; M. cinereopallida Coppins & Kantvilas (also known from Chile), with a granular to coralloid, goniocyst-like thallus containing superlatolic acid, pallid to piebald apothecia and (0–)1-septate ascospores, 8–15 × 2·5–5 µm; M. micromelaena Kantvilas & Coppins, similar to the widespread M. melaena but with markedly smaller, 0–1-septate ascospores, 8–12·5 × 2·5–4 µm; M. oreina Kantvilas & Coppins, characterized by a thallus of globose areoles containing gyrophoric acid, black, subglobose apothecia, and 1-septate ascospores, 11–16·5 × 4·5–6·5 µm; M. pallida Coppins & Kantvilas, similar to M. ceracea but distinguished by the presence of porphyrilic acid and relatively small, 3-septate ascospores, 9·5–15 × 2·5–4 µm; M. prasinastra Coppins & Kantvilas (also known from New Zealand), a member of the M. prasina group with a finely granular-sorediose thallus containing gyrophoric acid, unpigmented apothecia and (0–)1-septate ascospores, 7–11·5 × 1·8–3·5 µm; M. rubiginosa Coppins & Kantvilas (also known from Chile), likewise allied to M. prasina but with apothecia containing Rubella-orange pigment and ascospores 0–1-septate, 9·5–17 × 3·5–5·5 µm; M. sandyana Kantvilas, related to M. ternaria (Nyl.) Vĕzda but differing by smaller ascospores, 7–13·5 × 3·5–6 µm; M. saxicola Coppins & Kantvilas, characterized by a relatively thick, grey-brown, areolate thallus, convex, black apothecia and 0(–1)-septate ascospores, 7–18 × 4·5–7 µm; and M. tubaeformis Coppins & Kantvilas, related to M. flagellispora and with filiform ascospores, 45–100 × 1–2 µm, but differing by containing 2′-O-methylperlatolic acid and having funnel-shaped pycnidia. Ten species of Micarea are reported for Tasmania for the first time: M. almbornii Coppins, M. argopsinosa P. M. McCarthy & Elix, M. byssacea (Th. Fr.) Czarnota et al., M. contexta Hedl., M. farinosa Coppins & Aptroot, M. humilis P. M. McCarthy & Elix, M. incrassata Hedl., M. myriocarpa V. Wirth & Vězda ex Coppins, M. nowakii Czarnota & Coppins and M. pseudocoppinsii Brand et al. Also recorded for the first time for Victoria are M. alabastrites (Nyl.) Coppins and M. cinerea (Schaer.) Hedl. A key to Micarea-like lichens in Tasmania, which includes Micarea itself as well as Brianaria, Psilolechia and Leimonis, is presented. Leimonis erratica (Körb.) R. C. Harris & Lendemer and Brianaria tuberculata (Sommerf.) S. Ekman & M. Svensson are recorded for Tasmania for the first time.

A new lichenized fungus, Lecanora microloba Śliwa & Flakus, is described from the subnival belt of the Polish Tatra Mountains. It is characterized by small, saxicolous thalli with minutely lobulate marginal areoles and mostly broadly sessile and constantly pale coloured apothecia that are grouped predominantly in the centre of the thallus. Anatomically the species is distinguished by coarse granules in the epithecium which are distinctly bright in polarized light. The species contains gyrophoric and usnic acids, zeorin and an unknown terpene as secondary metabolites.

The lichen Caloplaca aurantia, when growing on concrete roof tiles, accumulates high concentrations of heavy metals. The uptake correlates with the ambient metal concentration. The results of lichen and substratum analyses of samples from a heavily polluted area indicate that the concentrations of metals in the lichen are many times higher than in the substratum. The relative content of the eight metals, Fe, Mn, Zn, Cu, Pb, Cr, Ni and Cd was determined. The content of Fe, Cr, Ni and Cd was not significantly different in the various tile zones sampled. Fe, Mn, Zn, Cu, Cr, Ni and Cd were mainly taken up by the lichen directly from the atmosphere. The uptake of these metals from the tile is almost negligible. The maximum uptake of Pb by C. aurantia from the tile glaze was 10.95°° of the total amount in the lichen. The presence of the lichen on the tiles prevents the penetration of Pb, Zn and Mn into the substratum.

Lichen communities were examined on 62 churches in Mecklenburg–Vorpommern, Germany. Ninety-six lichen species and subspecies, and three species of lichenicolous fungi identified. Tylothallia biformigera and Lecanora campestris subsp. dolomitica are reported as new Germany, and another 20 species are considered as threatened. This implies that the stone walls churches represent an extremely important habitat in Mecklenburg–Vorpommern, where natural outcrops are rare. The distribution of lichen species was analyzed quantitatively in relation to several habitat factors. Aspect, substratum and inclination were found to be important factors for 35, 34 31 species, respectively. The height of the relevé was a significant factor for many species. Twenty-three species, which are described in the literature with oceanic to suboceanic distributions, occur significantly more frequently near the coast. The ways in which microclimate affects each these habitat factors and contributes to the presence or absence of a species or group of species discussed. Some species have narrow and specific habitat demands, whereas others thrive under wide range of environmental conditions. The advantages of a strictly schematic approach with detailed statistical analysis are discussed.

Many lichen species have specific environmental requirements for colonization. Old-growth forests contain microhabitats required by a particular suite of lichens. In Ontario, Canada, old-growth forests are increasingly uncommon and the lichen communities within some of these forests are not well known. To better understand the lichen communities that inhabit old-growth forests in the province, we examined the lichen biota on coarse woody debris (CWD) and trees in a red pine (Pinus resinosa) and a white pine (Pinus strobus) dominated stand in northern Ontario. Lichen diversity was assessed on different forms of CWD and trees in each forest. Lichen diversity did not differ significantly between CWD types in the red pine forest, but was significantly different in the white pine forest. There was no significant difference in lichen diversity amongst different decay stages of CWD in either forest. In both forests, lichen communities on stumps, logs, and snags differed from lichen communities present on trees. A variety of CWD types is important for overall lichen species richness in the red pine forest. Our results demonstrate to land managers that different types of old-growth forests are ecologically unique, even those dominated by tree species in the same genus. Management of an old-growth forest should suit its individual ecology.

The term ‘phycolichens’ has recently been introduced as a synonym for ‘green algal lichens’ i.e. those having phycobionts as their primary autotrophic partner, which is analogous to the contracted term ‘cyanolichen’. However, a study of the history of the term ‘Phycolichenes’ leads us to suggest that this term should not be applied because of considerable ambiguities in past usage and the possibility of confusion. The term was first created by E. Fries in 1831, and was used later by Massalongo as a taxon for homoiomerous cyanobacterial lichens. With this, or similar meanings, it remained in use until the middle of the 20th Century. Diels (A. Engler's Syllabus der Pflanzenfamilien, Gebr. Borntr., Berlin, 1936) defined the same expression Phycolichenes as lichens with Phycomycetes as mycobiont, and this definition can still be found in recent literature. If a shortened term for green algal lichens is needed then we suggest ‘chlorolichens’ as a better counterpart to cyanolichens.

Bryoria chalybeiformis, as commonly interpreted, is an almost exclusively saxicolous or terricolous species with a largely arctic-alpine distribution; it produces small amounts of fumarprotocetraric acid in the soralia. The terricolous form of B. fuscescens var. positiva, distributed from sea level to the high mountains, is distinguished by the production of abundant fumarprotocetraric acid accompanied by protocetraric acid. B. intricans appears to be closely related to B. chalybeiformis and may possibly represent an environmentally induced morphotype of it. Attention is drawn to nomenclatural problems connected with B. chalybeiformis.

The Southern Hemisphere genus Psoromidium Stirton (Lecanorales, Pannariaceae) is closely related to certain elements within the heterogeneous genus Psoroma Michx, but is distinguished by the absence of a photobiontin the apothecial margin. In Psoromidium, as in Psoroma, the main photobiont is green and is present in a layer below the upper cortex of the squamules; Nostoc occurs in scattered, well-defined cephalodia. Two species are known: P. aleuroides, with an Australasian distribution, and P. versicolor, anaustral species from Tasmania, Fuegia and the subantarctic Auckland Islands group of New Zealand. Anatomy, morphology, distribution, habitat ecology and taxonomy of the two species are discussed. Psoromaria Nyl. is a synonym of Psoromidium.

Verrucaria canella, V. fuscella and V. polysticta occur in Great Britain and Ireland; these species have been widely confused, and have often incorrectly been called V. glaucina. Similar specimens parasitic on Aspicilia caesiocinerea may belong to an additional, undescribed species. A lectotype is selected for V. fuscella.

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.

A broad generic concept is adopted for Catillaria, and the following new combinations made: C. aphana (Nyl.) Coppins, C. modesta (Müll. Arg) Coppins (the basionym, Lecidea modesta Müll. Arg., being lectotypified), C. picila (Massal.) Coppins, and C. scotinodes (Nyl.) Coppins. Lecidea botryiza Nyl. ex Stirton is added to the synonymy of Micarea lutulata. Catillaria rhypodiza is transferred to Halecania, and a new, sorediate, corticolous species of that genus, H. viridescens Coppins & P. James, is described.

Usnic acid is a unique lichen metabolite of industrial importance, widely studied to explore its pharmacological potential and valued especially as an antibacterial agent in cosmetics. Although a vast number of papers describe usnic acid extraction from various lichen species, none has so far provided an unequivocal indication of the best extraction procedure for this compound. Thus, the current study was focused on the direct comparison of three commonly used usnic acid extraction methods (heat reflux, shaking, ultrasound-assisted extractions), which were optimized using fractional factorial design. Heat reflux extraction, shaking extraction and ultrasound-assisted extraction were first optimized in a series of experiments using fractional factorial design, with respect to three parameters: the extraction time, the solvent used and the number of extraction repetitions. HPLC was employed for usnic acid quantitative analysis. The best scores for each extraction method were statistically compared and the optimal conditions were indicated. The optimal set of parameters for usnic acid was established to be a single, 60 min heat reflux extraction with acetone. This extraction scheme provided 4.25 ±0.08 mg g−1 d.w. of usnic acid, while for ultrasound-assisted and shaking extractions the amount was two- or even four times lower (2.33 ±0.17 and 0.97 ±0.08 mg g−1 d.w., respectively). The optimal procedure for usnic acid extraction described here may be suitable for effective acquisition of this compound for scientific research purposes, but also for applications in the pharmaceutical or cosmetic industries.

Lecanora albescens (Hoffm.) Branth & Rostr. is the correct authorship of this species, and the combination cannot be attributed to Flörke. Lecanora antiqua J. R. Laundon is described for the lichen previously, but wrongly, known in Britain as L. conferta; it is remarkable in occupying the interface between acid and calcareous surfaces on the vertical walls of medieval churches. The nomenclature of the lobed Lecanora, which has had two alternative Latin names since the early 19th century, namely L. muralis Rabenh. and L. saxicola (Pollich) Ach., has been studied and the latter was found to be correct.

The new genus of lichenicolous fungi Austrostigmidium is described from Antarctica and Tierra del Fuego (Chile). It is characterized by the presence of black pseudothecia, pseudoparaphyses, fissitunicate, I−, KI− asci and 3-septate hyaline ascospores. So far, the only known species grows on Mastodia tessellata (Verrucariales, Eurotiomycetes). The new genus is compared with anatomically close genera. Based on nuLSU and nuSSU markers we inferred its phylogenetic relationships and found that it belongs to the family Teratosphaeriaceae (Capnodiales, Dothideomycetes) and is closely related to rock-inhabiting fungal species, as well as to the hyphomycetous lichenicolous fungus Xanthoriicola. Finally, the host-parasite interface has been analyzed by means of transmission electron microscopy and fluorescence microscopy in order to describe the interactions among the new fungus and the symbionts forming the host lichen.

The following new corticolous species are described. Thelopsis cruciata Aptroot & M. Cáceres, with an olive-green thallus, immersed red-brown perithecia and c. 50–100 cruciate ascospores per ascus, 7–10×4–7 µm, from Brazil. Topelia argentinensis Aptroot, L. I. Ferraro & M. Cáceres, with a verrucose, partly almost isidiate, greenish grey thallus, immersed pinkish perithecia and 8 uniseriate muriform ascospores per ascus, 12–17×7–11 µm, from Argentina. Topelia tetraspora Aptroot & M. Cáceres, with a c. 0·1–0·6 mm thick layer of coralloid to usually flattened, irregularly palmately branched isidia c. 0·05 mm diam., ascospores 15–19×2–6-septate, muriform, ellipsoid, 39–50×11–16 µm, only up to 4 per ascus maturing, from Brazil. Thelopsis inordinata is reported for the first time from South America, from Guyana. A key is given to all currently known species of Topelia and Thelopsis. The distinction between these genera has become arbitrary with the recent addition of more or less intermediate species.

The quantitative response to two lichen metabolites, vulpinic acid and (+) usnic acid, on biomass production by the photobiont Trebouxia irregularis, isolated from the lichen Cladina mitis, was determined experimentally. The presence of usnic acid resulted in inhibition of photobiont growth, and the effect depended on the pH of the culture medium. The concentration effect of usnic acid was observed. The application of vulpinic acid almost completely inhibited the growth of T.irregularis and no significant differences were found among samples at different medium pH values.