Verrucaria elaeina Borrer is a misunderstood species of shaded which is widespread in the British Isles. It resembles the freshwater species V. praetermissa, but differs in the more prominent perithecia, the lack of a layer, the slightly smaller ascospores, and the lack of a perispore.

The genus Skyttea is characterized by urceolate ascomata, with a narrow pore when young, a greenish or brownish, rarely reddish exciple of conglutinate hyphae with subglobose to ± cylindrical lumina, bordered near the margin by hyaline to greenish or brownish, usually smooth, straight hairs, the absence of periphyses, rarely branched and apically hardly thickened paraphyses, asci and a hymenium that are entirely I — and KI —, a thin lateral and a very thick apical ascus wall with a small ocular chamber, and normally aseptate ascospores. It is considered to belong to the Leotiales and not to the Ostropales. It comprises at least 17 species, including S. caesii sp. nov., S. carboneae sp. nov., S. lecanorae sp. nov., S. mayrhoferi sp. nov., S. pyrenulae sp. nov., S. radiatilis comb, nov., S. tavaresae. sp. nov. and S. thelotrematis sp. nov. Rhymbocarpus is shown to be a distinct leotialean genus, distinguished from Llimoniella by a different excipular structure, different pigments and the presence of excipular hairs, which, in some species, are embedded in the excipular gel and thus not visible macroscopically. In addition to the type species, R. geographici, of which a neotype is designated, it includes R. boomii sp. nov.,R. cruciatus comb, nov., R. fuscoatrae comb, nov.,R. makarovae sp. nov.,R. neglectus comb, nov., R. pertusariae sp. nov.,R. pubescens comb. nov. and R. stereocaulorum comb. nov. Llimoniella s. str. comprises at least 6 species, including the type, L. scabridula, L. adnata, L. pertusariae sp. nov., L. pyrenulae sp. nov., L. ramalinae comb. nov. and L. vinosa comb. nov. Several species formerly assigned to Skyttea or Llimoniella are now included in the leotialean genus Unguiculariopsis, and the following new combinations are proposed: Unguiculariopsis acrocordiae comb, nov., U. groenlandiae comb. nov. and U. lesdainii comb. nov. A lectotype is chosen for Lichen stictoceros, which is shown to be a synonym of Evemia prunastri. Keys are given for the species of Skyttea, Llimoniella and Rhymbocarpus, and for the lichenicolous genera of Leotiales and Ostropales.

The minimal area of a foliicolous lichen community of Woessia vasakii in southern France (West Languedoc, Department of Gard) was studied by the method of the mean similarity coefficients of Sørensen and of Kulcinsky. The determination of the qualitative and quantitative minimal areas, which are c. 30–50 cm2 and 50–80 cm2, respectively, allows the phytosociological study of the foliicolous communities of southern France by the method of integral sampling.

The biomass of lichens and its vertical distribution on trees were investigated in a > 100-year-old boreal forest in central Finland. The lichen biomass on individual trees was 1292–3669 g tree−1 on Picea abies and 742 g tree −1 on Pinus sylvestris. More than half of the biomass occurred on dead branches. The proportion of Hypogymnia physodes appeared to rise with the canopy height while the other lichens (Platismatia glauca, Bryoria spp. and Pseudevernia furfuracea) decreased. Mean total lichen biomass for sampled trees on an aerial basis was 163 gm −2. The standing crop of litter lichen deposited on ground was about9 gm −2.

The anatomy of Xanthomaculna convolute shows adaptation to a vagrant life form and to the moisture conditions of its habitat. The differential swelling of the irregularly thickened upper cortex and the medulla, in addition to the rigid medullary structure, due to the deposition of calcium oxalate, allow orderly hygroscopic thalline movements. The architecture of the medulla appears to be closely related to masonry-like arches where the material is only stressed by compression and the stresses are distributed at the hinges. The possible role of crystalline medullary deposition as a radiation reflector is also suggested.