The genus Micarea was studied for the first time in the Taita Hills, Kenya. Based on new collections and existing data, we reconstructed a phylogeny using ITS, mtSSU and Mcm7 regions, and generated a total of 27 new sequences. Data were analyzed using maximum likelihood and maximum parsimony methods. Based mainly on new collections, we discovered four undescribed well-supported lineages, characterized by molecular and phenotypic features. These lineages are described here as Micarea pumila, M. stellaris, M. taitensis and M. versicolor. Micarea pumila is characterized by a minutely granular thallus, small cream-white or pale brownish apothecia, small ascospores and the production of prasinic acid. Micarea stellaris has a warted-areolate thallus, cream-white apothecia usually darker at the centre, a hymenium of light grey or brownish pigment that dissolves in K, and intense crystalline granules that appear as a belt-like continuum across the lower hymenium when studied in polarized light. Micarea taitensis is characterized by a warted-areolate thallus and cream-white or yellowish apothecia that sometimes produce the Sedifolia-grey pigment. Micarea versicolor is characterized by a warted-areolate, sometimes partly granular thallus and apothecia varying from cream-white to light grey to blackish in colour. This considerable variation in the coloration of its apothecia is caused by an occasional mixture of the Sedifolia-grey pigment in the epihymenium and another purplish brown pigment in the hymenium. Micarea stellaris, M. taitensis and M. versicolor produce methoxymicareic acid. The main distinguishing characters are presented in a species synopsis. Three of the new species are nested in the M. prasina group, and the fourth one (M. taitensis) resolves as a basal taxon to the M. prasina group. The new species inhabit montane cloud forests, which have fragmented dramatically throughout the Eastern Arc Mountains in recent decades.

Lichen cover and diversity were analysed on the dwarf shrub Helianthemum oelandicum (L.) Dum.Cours. at one site in the calcareous grassland of the area known as the ‘Great Alvar’ on the Island of Öland, Sweden. The age of 22 phorophytes was determined by ring counting and varied from 8 to 41 years and was accurately predicted by the root diameter. A total of 18 lichen species was found, with a range between 0 and 13 species per phorophyte. The number of lichen species on living H. oelandicum were correlated with the phorophyte age. The number of lichen species and their coverage were greater on dead compared with living phorophytes. The species number was also higher on thin branches compared with thick branches and roots and some of the species showed preferences for dead phorophytes, and for thin branches. This study of lichen colonization and growth on dwarf shrubs in relation to phorophyte age is a new application of herbchronology.

The new species Arthothelium desertorum is described from the Namib desert. It is characterized by its saxicolous habit and areolate thallus containing divaricatic acid.

John Lightfoot's account of lichens in Flora Scotica was the first Scottish lichen Flora and as such it was novel in several respects: 1) it was published in English; 2) it drew on the knowledge and expertise of several key local collectors and treated lichens from alpine areas for the first time; 3) it made lichens accessible in providing Linnaean binomials, colloquial English, and frequently also Gaelic names, together with lively descriptions, details of ecology, and medicinal or traditional uses when these were known. Of the 117 taxa listed, 109 were classified in the genus Lichen, five in Byssus, two in Mucor and one in Fucus. Nineteen taxa were newly described, of which five are still in current use. John Lightfoot's life, work and botanical friendships are also briefly discussed.

Eight new species of Xanthoparmelia (Parmeliaceae) are described from eastern Australia: X. biloelensis Elix, X. fracticollis Elix, X. kosciuszkoensis Elix, X. nerrigensis Elix, X. paratasmanica Elix, X. rankinensis Elix, X. remanella Elix and X. stuartioides Elix. In addition, a further ten new state records of Xanthoparmelia are reported from eastern Australia.

The two corticolous species Fuscidea lightfootii (Sm.) Coppins & P. James and F. pusilla Tønsberg are morphologically and chemically similar and it has been suggested that they are conspecific. We investigated the interspecific relationship between F. lightfootii and F. pusilla using ITS, LSU and mtSSU rDNA. The combined multigene phylogeny shows that these species are genetically distinct. They are similar in ascocarp anatomy but in thallus morphology and substratum preferences there may be slight differences between them. Moreover, F. pusilla displays a broader ecological range than F. lightfootii. Even though some morphotypes appeared distinct and may be assigned to one of the two species with some degree of certainty, the use of DNA sequencing is recommended for their identification. Epitypes are designated for both species.

A taxonomic investigation of Lethariella smithii and L. zahlbruckneri has established that they are conspecific. Three chemical races are recognized: race 1 containing norstictic acid, race 2 norstictic acid and placodiolic acid, and race 3 placodiolic acid as major medullary substances.

The new species Opegrapha subdictyospora is described from NE Brazil. It is only the third species in the genus with (sub)muriform ascospores and is further characterized by the brown pruinose discs. It was collected at Vale do Catimbau National Park in Pernambuco, which is a Caatinga area, where it is locally common.

In 1915 Hue described Lecanora (sect. Placodium) aequata growing over quartzite rocks from Busan and the Kangwon Provinces of South Korea. Later Zahlbruckner (1931) transferred it to the genus Caloplaca. Careful examination of syntype material of L. aequata lodged at The Natural History Museum, UK (BM) demonstrates that the species is conspecific with C. cinnabarina (Ach.) Zahlbr. and we henceforth synonymize it with that species.

Eighty-seven lichen taxa were collected at four localities near the leadzinc mine at Maarmorilik. These are listed alphabetically and grouped according to their ecological preferences. Lichens, which in Greenland are restricted to calcareous rocks and alkaline soil substrata, are well represented in the Maarmorilik area. In contrast, ferrugineous lichens appear to be comparatively rare. The lichens around the mining town are assumed to have accumulated significant concentrations of airborne lead and zinc. However, no damage to the lichens caused by heavy metals was observed.

A set of artificial keys is presented to all those crustose lichens (except most species of Lepraria and Leprolomd) which commonly occur without fruiting bodies on rock or soil in the British Isles. A number of predominantly corticolous species that occasionally also occur on rocks are included, as well as several undescribed but well-understood entities.

Growth of the mycobiont of Ramalina siliquosa and the secondary metabolites subsequently produced under various osmotic culture conditions were examined. The secondary metabolite content and the growth rate changed greatly when different quantities of sucrose were added to the culture medium. Salazinic acid was found only in mycobionts cultured on a medium with 10 or 20% sucrose, the mycobiont growth rate being higher than on conventional medium. Similarly, in Lobaria discolor, gyrophoric acid was found only in mycobionts cultured on a medium with 10% sucrose.