An account of the lichens of the Ben Lawers–Meall nan Tarmachan area is provided. After re-evaluating the older records, 431 species are accepted as having been reliably recorded from high ground of which 118 are reported for the first time. These include Bacidia carneopallida, Caloplaca ammiospila, C. approximata, Catapyrenium daedaleum, Ionaspis cyanocarpa, Micarea crassipes, Ochrolechia inaequatula, Omphalina pararustica, Phaeophyscia endococcina, Porocyphus rehmtcus, Protolhelenella leucothelia, Stereocaulon tornensis, and Toninia fusispora new to the British Isles. Rarities are particularly numerous on the summit cliffs and in the Lochan nan Cat corrie. An ecological description of the lichen flora of the main localities is provided. Evidence is advanced that this concentration of arctic-alpine lichens is a result of the coincidence of strongly calcareous bands within the mica-schist, an unusually severe climate, and the rugged topography which provides extensive outcrops right to the summit. The lichen flora is probably the most outstanding feature of the botany of Ben Lawers; this survey confirms the international importance of the area. One new species, Pyrenopsis multispora Coppins, is described and three new combinations are made: Bacidia carneopallida (Müll. Arg.) Coppins, B. tetramera (de Not.) Coppins, Kiliasia scotinodes (Nyl.) Coppins.

Verrucaria simplex McCarthy is described as new from northern England. Verrucaria granulosaria Clauz. & Zehetl. and V. papillosa Ach. are recorded for the first time in the British Isles.

In the recently deglaciated zone of a valley glacier in Central Ellesmere Island the mean period of time before the onset of colonization on bare rock surfaces was estimated to be about 80 years. The first species to establish was Xanthoria elegans, followed by Lecanora crenulata and Umbilicaria virginis approximately 20 years later. Summer temperature appeared to be one factor which affected lichen establishment in recently deglaciated bare areas in the High Arctic. Warmer microsites were identified as preferred locations for thallus establishment; these, therefore, constitute ideal sites for studies of thallus initiation under natural conditions. Following the retreat of a glacier from its most advanced Little Ice Age position, 16 species of saxicolous lichens have become established on bare rock debris in the icefree zone, but in nine transects only five species had a constancy of 80% or more. Lichen diversity in this successional photocommunity was comparable to that in a nearby pre-Little Ice Age landscape with more varied substrata.

Specimens of Dictyonema glabratum from various elevations in the Venezuelan Andes show clear differences in morphology. Optimal development of thalli is attained in the lower Paramo at 3500–3600 m; at the upper altitudinal limit of distribution at about 4300 m only poorly developed thalli are found; in the montane forest zone at about 1700 m the thalli attain about half the average surface area and two thirds of the thickness of those in the optimal habitat. The histological structure of the thalli also shows significant differences. The relative volumes of photobiont to mycobiont, as an indicator of the relationship autotrophism/heterotrophism, is 1.6:1 in specimens from the upper Paramo; 0.9:1 in open habitats on the lower Paramo; 0.5:1 in shaded habitats; and 1.4:1 in the montane forest. The three altitudinal morphotypes are not only distinguished by structure but also by carbon dioxide gaseous exchange patterns. Specimens from the optimal habitat exhibit the highest photosynthetic capacity. The respiration activity reflects a homeostatic adjustment to the prevailing temperature regime: the respiration of specimens from 4300 m at 1°C approximates to same intensity as that of D. glabratum from the lower Paramo zone at 6°C. Nevertheless, metabolic homeostasis is only possible over a narrow temperature amplitude. On account of the large heterotrophic component in lichens, at altitudes below 1500 m where the temperature average is 20°C or more and the nocturnal temperatures are constantly high, the dry matter consumption due to respiration would become extremely high. This suggests that D. glabratum may be limited in its downward distribution by an increasingly unfavourable carbon budget.

Thirty-five species of lichens were collected from nine locations on or adjacent to the Navajo Indian Reservation in the southwestern United States. Wool was dyed using the traditional boiling water and ammonia fermentation methods. An additional method was developed using a solvent to extract lichen substances and dye wool, cold; this dimethylsulphoxide extraction method is described and the resulting dye colours were sometimes different. Over 155 individual dye tests were made on sheep's wool; a correlation of dye colour with lichen substances reported for the species was attempted. Predominant dye colours were tan, but yellow, orange, pink, purple, and blue-grey were also produced. These colours were further altered by modifying: (1) fermentation time; (2) dyeing time, temperature, or pH level; (3) exposure to light; and (4) subsequent additional extractions using the same method or different methods. Dyed wool samples, tested for stability in sunlight, generally faded to some degree and some changed colour. Most dyes obtained through the dimethylsulphoxide extraction method were light stable.