The first sorediate species in the genus Llimonaea, L. sorediata is described from coastal areas of western Europe. This new species is easily mistaken for Dirina massiliensis f. sorediata with which it often co-occurs. It grows on vertical or overhanging acidic cliffs. Fertile specimens were recently collected in Portugal. A description of the species together with notes on distribution, ecology and chemistry are provided and a key to the species of Llimonaea is also provided.

A relatively quick and simple method is presented for monitoring changes in distribution and in site and substratum preferences of epiphytic macrolichens; the method also records the natural turnover of common species. Changes in the epiphytic lichen flora in southern Sweden were recorded at 64 sites in 1986 and again in 2003. In total 1990 observations of lichens were recorded on 15 tree species, mainly on trunks but also on branches up to 2 m above the ground. Almost all species showed a high turnover with regard to substratum, including very abundant species such as Hypogymnia physodes. Many of the species had changed substratum within their sites, possibly reflecting a general change in the ecological quality of sites. Canonical Correspondence Analysis was used to extract the variation in species composition over time, using 1685 records of 55 lichen species on 8 different substrata. Some species such as Hypogymnia tubulosa had increased in abundance whilst others such as Vulpicida pinastri had decreased.

The sorediate variety of Sclerophytomyces circumscriptus (Taylor) Sparrius & P. James (Roccellaceae, Arthoniales) is described from sheltered, acid rock along Europe's western coasts and the Atlantic islands. This sorediate taxon is reported from the British Isles, Ireland, France, Spain, Portugal, the Azores and the Canary Islands. A description of the morphology, distribution and ecology is provided. The phylogenetic position of the new taxon is discussed, as well as nomenclatural and orthographic issues. The name Sclerophytomyces is proposed as an orthographic correction of the published name Sclerophytonomyces.

Myriospora signyensis Purvis, Fdez-Brime, M. Westb. & Wedin is described from Signy Island, South Orkney Islands, Antarctica, where it occurs predominantly on quartz mica schist. This represents the first record of the genus for Antarctica. The distinctive interrupted photobiont arrangement places it within the genus Myriospora (formerly known as the ‘Acarospora’ smaragdula group, or Silobia). The new species is characterized by having large, distinctly elevated, sessile apothecia with a prominent margin and a thallus that is usually lobed at the margins and variously orange-red, rust-coloured or brown-pigmented. Molecular phylogenetic analyses inferred with strong support that M. signyensis is closely related to M. scabrida which is similar in having a lobed, imbricate thallus with large and frequently somewhat raised apothecia, but which differs in never being rusty red, by frequently having a larger number of apothecia per areole/squamule and by having a thick and distinctive thalline epinecral layer. Myriospora signyensis is otherwise most similar to M. dilatata but the thallus of M. dilatata is never imbricate-lobate and the ascomata of M. signyensis have larger and more distinctly raised and sessile apothecia. A worldwide key to the 10 species currently recognized in the genus is presented.

Lecanora paramerae is described from Central-East Spain. At the only two known localities it grows on Juniperus thurifera trees in the ‘Serranía de Cuenca’ mountains. It is chemically characterized by the presence of 2′-O-methylperlatolic acid in addition to atranorin and psoromic acid. Anatomically, it can be recognized by the presence of large and irregular crystals in the amphithecium, a pulicaris-type epihymenium and broadly ellipsoid ascospores.

The sensitivity of Hypogymnia physodes, Lobaria pulmonaria and Peltigera aphthosa to six photosystem II herbicides and to DBMIB was tested in the laboratory by chlorophyll fluorescence and oxygen-exchange measurements. In addition, experiments with freshly isolated photobiont cells from H. physodes and L. pulmonaria were performed. Generally, the lichens were most sensitive to the urea herbicides diuron and isoproturon, whereas the triazines atrazine, terbuthylazine, and simazine and the triazinone metamitron were less inhibitory. Among the three lichen species investigated, H. physodes was the most sensitive to the urea herbicides. For the other agents, no significant differences between lichen species could be found. The highest pI50 values obtained from dose response curves were around 6.5 for isolated photobionts, but most values for lichen thalli were in the range 5–6. Thus, there is no particular sensitivity of green algal lichen photobionts to photosystem II herbicides as compared to other algae, higher plant chloroplasts or protoplasts. In nature, we observed recovery from (damaging) treatment with 10−5 mol diuron 1−1 for H. physodes within weeks. Therefore, damage to lichens from the use of photosystem-II herbicides in agriculture is probably only of very local occurrence.

Belonia mediterranea Nav.-Ros. & Llimona sp. nov. is described and compared with other, mainly saxicolous, species of the genus. It is known only from the type locality, Medes Islands (Catalonia, NE Spain), where it occurs on shaded limestone cliffs, near the Mediterranean seashore. It differs from related saxicolous species of Belonia mainly in the appearance of the thallus, ascospore septation and ecology. A key to the European species of Belonia is provided.

Thelidium austroatlanticum sp. nov. is described from Signy island; it is characterized by an epilithic thallus, more or less appressed involucrellum, and 1-septate spores 30–40 μm long. Thelidium incavatum is also reported for Signy Island.

Usnea elixii sp. nov. is a restricted endemic of north Queensland. It is usually fertile, but produces a continuum of morphs, with the other extreme being a sterile isidiate morph with large pseudocyphellae. All morphs produce protocetraric acid.