Five corticolous taxa of sorediate Ramalinae which occur in the tropics and subtropics are shown to comprise the tropical component of the otherwise temperate Ramalina farinacea complex. Their morphology, anatomy, chemistry, ecology and distribution are discussed. Ramalina pacifica Asah., R. nervulosa (Müll. Arg.) des Abb., R. dumeticola Krog & Swinscow and R. luciae Mohlo et al., were investigated together with an unnamed acid-deficient taxon. Ramalina nervulosa and R. pacifica are maintained as species while the remainder are considered as varieties of these species; viz. R. nervulosa var. dumeticola (Krog & Swinscow) comb. nov., R. nervulosa var. luciae (Mohlo et al.) comb. nov., and R. pacifica var. inacida var. nov.

The lichen vegetation of a limestone pavement in the Burren region of western Ireland is described. Species are distributed in relation to gradients of moisture, nutrient-availability and insolation; these in turn may be related to the range of geomorphological micro-features associated with karst. The majority of the 136 stands are dominated by endolithic and foliose cyanophilic lichens. Epilithic, non-cyanophilic crusts grow best on surfaces subjected to occasional bird-manuring. A successional sequence from bare rock through endolithic communities to ones dominated by epilithic, noncyanophilic species does not occur in the Burren.

Measurements of thalli of Rhizocarpon geographicum on the recent moraines of the Glacier de Valsorey and their surroundings are considered in relation to thallus growth rates and colonization following glacial recession. Photographs taken in 1975 and 1979 show that up to c. 3.5 cm diam the relation of maximum growth-rate to thallus size is approximated by a growth curve of the kind derived by Aplin and Hill, rising asymptotically towards a constant rate of radial growth (here c. 0.5 mm year−1). Growth-rates of many individual thalli fall well below the maximum. Parameters of the fitted growth curves are used to construct curves of thallus radius against time. Taken in conjunction with the field measurements these suggest two main phases of colonization, one from about 1880 to 1910, and one from about 1930 onwards. Some general considerations relating to lichenometry and lichen growth curves are discussed.

Descriptions are given of two little-known species of Brigantiaea (Lecanorales, Brigantiaeaceae) which are widely distributed in New Zealand. Brigantiaea lobulata F. J. Walker & Hafellner sp. nov. is described and the following new combinations are proposed: B. tabacodes (Zahlbr.), B. nipponica (Sato) and B. austroamericana (Räsänen), combs. nov.

Seventeen saxicolous species of Rinodina are recognized in New Zealand, including five species new to science (R. gallowayii, R. jamesii, R. murrayii, R. nigricans and R. tibellii spp. nov.), one new combination (R. otagensis (Zahlbr.) comb, nov.), and six new records (R. bischoffii, R. gennarii, R. immersa, R. lecanorina, R. lecideina and R. teichophila). Names of five taxa in Buellia have been placed in synonomy. Distributional data are provided for all species. A key is given, and the various definitive spore types are illustrated.

Twenty-nine species of foliicolous lichens are reported from Zimbabwe. Arthonia nigratula (Müll. Arg.) R. Sant. is mentioned for the first time in Africa, and Catillaria vandenberghenii sp. nov. is described.