A selected bibliographic guide to publications on the lichen floras of the world arranged by continent and country is provided. This is supplemented by information on further sources of data, including world monographs, literature compilations, lichenological journals, exsiccatae, and compendia of herbaria. About 1390 references to the literature are provided. An index to countries and islands treated is included.

Eight species ofPseudocyphellariaare recorded from mainland Ecuador viz., P. arvidssonii, P. aurata, P. bartlettii, P. clathrata, P. crocata, P. dozyana, P. encoensis and P. intricata, with taxa asterisked being new records for Ecuador. Pseudocyphellaria bartlettii andP. encoensis are also new records for northern South America, and P. dozyana is new to South America. A key is given, and details of anatomy, morphology, chemistry, distribution, ecology and taxonomy are discussed.

The status of four umbilicate lichens with lecanorine apothecia and hyaline, 1-celled ascospores is reviewed. It is concluded that Omphalodium should be emended to exclude O. arizonicum and consequently a new genus Omphalora T. Nash & Hafellner is proposed. Differences in anatomy, morphology, pseudocyphellae type, pigmentation and cell wall chemistry, and ascal dehiscence provide the primary justification for the new genus.

The byssoid lichen genus, Roccellinastrum, consists of three species in Tasmania.Two of these, R. flavescens and R. lagarostrobi, are described as new. Both species grow exclusively on the leaves of Tasmanian endemic conifers and are recognized by a combination of morphological, chemical and anatomical characters. Usnic acid, found in R. flavescens, is recorded in the genus for the first time. Relationships with South American species are discussed.

A description of the lichen communities associated with natural rock outcrops and derelict mine workings in the upland region of Dartmoor, south-west England, is presented. An examination of 34 study sites revealed 270 taxa, of which 28 are reported as new to Devon including several national rarities. Notes on 29 tors have been prepared and reasons for the predominance or decline of particular communities or species are discussed.

The following new combinations are made: Anema cernohorskyi (Servít) Henssen, A. prodigulum(Nyl.) Henssen, Cryptothelelaatokkaënsis (Vainio) Henssen, C. rhodosticta (Taylor) Henssen, Gonohymenia heppii (Müll. Arg.) Henssen, G. iodopulchra (Crozals) Henssen, G. minnesotensis (Fink) Henssen, G. polyspora (Magnusson) Henssen, G. schleicheri (Hepp) Henssen, Metamelanea caesiella (Th. Fr.) Henssen, Paulia myriocarpa (Zahlbr.) Henssen, P. pyrenoides (Nyl.) Henssen, P. schroederi (Zahlbr.) Henssen, Peccania arabica (Müll. Arg.) Henssen, P. teretiuscula (Flagey) Henssen, P. tiruncula (Nyl.) Henssen, Pterygiopsis coracodiza (Nyl.) Henssen, P. umbilicaia (Vezda) Henssen, Thelignya groenlandica(Dahl) Henssen, T. Hgnyota (Wahlenb.) P. M. Jørg. & Henssen, Thyrea pachyphylla (Müll. Arg.) Henssen, T.pachyphylla var. laxa (Müll. Arg.) Henssen. The following new names (one as a new species) were found necessary: Pyrenopsis haematina P. M. Jørg. & Henssen and Thyrea confusa Henssen. New synonyms are given for several names. The world-wide distribution of the genera Phloeopeccania and Pterygiopsis is mentioned.

The genus Japewia Tønsb. is introduced to accommodate three species including J. subaurifera Muhr & Tønsb. sp. nov. based on material from Norway, Sweden, Finland, Scotland, Canada (British Columbia) and U.S.A. (Washington). This species is closely related to Lecidea tornoensis Nyl. but is distinguished in being sorediate and by the production of lobaric acid (accessory) and acetone-soluble pigments. It grows on bark of deciduous and coniferous trees. Lecidea carrollii Coppins & P. James and L. tornoensis Nyl. are transferred to Japewia.

The genus Pterygiopsis Vainio (Lichinaceae), originally described from Brazil, is shown to have two species in Northern Europe: P. coracodiza (Nyl.) Henssen growing on irrigated rocks in N.W. Europe (France, Great Britain, W. Sweden and Norway), and P. lacustris P. M. Jørg. & R. Sant. sp. nov. occurring ± submerged in some lakes in S. Sweden.

The lichen colonization of recently created urban wasteland is described by referenceto 40 sites in England, Scotland and Wales. The 100 species encountered form a series of overlapping communities in which successional relationships over the first 16 years have been investigated. Floristic variation within towns tends to be greater than variation between them. Ona national scale climatological, geological and historical factors appear to play only a small part in determining the composition of this pioneering flora. Many species can be accommodated within the strategy group stress-tolerant ruderals; a few possess the character of ruderals. The heyday of this component of the urban flora may be drawing to a close. Acarospora heppii f. luteopruinosa, Lecidea polycarpella and Micarea excipulata are reported as new to Britain.

Survival strategies of 34 species of lichens from a range of substrata, climates and growth forms were examined using the triangular ordination procedure of Grime. Triangular ordination is apparently an appropriate technique to apply to lichens, all available data falling within a triangle except for two foliicolous species which are probably partial leaf parasites. Statistically significant relationships between survival strategy and growth form, mode of asexual reproduction, substratum preference, family affiliation, and diversity of secondary chemical biosynthetic pathways have been demonstrated.

The composition and richness of the microfauna on lime trees was surveyed in relation to the distribution and cover of lichens in Belfast. Parameters used to help interpret the results included distance from the city centre and available data on air quality. The percentage epiphyte cover on the trunks of lime trees was significantly correlated with distance from the city centre whereas that on tree bases as not. In contrast, the number of microfaunal species revealed strong positive correlations with distance for both the bases and the trunks of trees. Most of this increase in microfaunal species richness towards rural areas was due to protistans which are thus proposed as useful bioindicators of air pollution. The total species richness of fauna showed slight negative correlation with smoke but not SO2 levels.

A second species of the lichen-forming hyphomycete genus Cheiromycina B. Sutton, C. petri D. Hawksw. & Poelt sp.nov., is described from old Betula bark in Steiermark, Austria. It differs from C. flabelliformis B. Sutton in thallus colour, the more compact blue-grey non-eroding sporodochia, the very tightly dichotomously branched conidia, and in having much shorter terminal branches.

Lecanora creatina Norman ex Th. Fr. and Lecanora leucophyma Leighton were found to be synonyms of Koerberiella wimmeriana (Körber) B. Stein; both represents the isidiate growth form of the species. The lichenicolous fungi Arthonia almquistii Vainio, Endococcus propinquus (Körber) D. Hawksw. and Sagediopsis aquatica (B. Stein) Triebel occurs on K. wimmeriana. All are described in detail.