Lecanora compallens and L. sinnosa, two corticolous lichens, are described nas species new to science on the basis of numerous collections. Lecanora compallens is a sorediate species, known only as sterile. It is probably common in Western Europe, but overlooked because it is very similar to L. expallens. Chemically, the new species is identical with L. strobilina, of which it may represent a sorediate counterpart. Lecanora sinuosa is a new species similar to L. chlarotera and so far only known from a limited area in the Netherlands and Germany, although it may be overlooked elsewhere. Lecanora sinuosa is very close to L. hybocarpa with which it shares the puhcaris-type epihymenium inspersed with fine crystals but differs markedly by its thick thallus and thick and sinuous apothecium margin.

Steinia australis Kantvilas & P. M. McCarthy is described, based on a specimen from Tasmania. The new species, the second in the genus and only the third in the family Aphanopsidaceae, differs from S. geophana by its larger ascospores, well-developed exciple and scurfy, leprose thallus.

Two new species of Micarea are described from South Africa: M. almbornii Coppins, on loose sandstone from Stellenbosch (Western Cape) and M. endoviolascens Coppins, on damp soil from Transvaal. A note is given on Lecidea geïna Stizenb.

Sulcopyrenida H. Harada gen. nov. is described. It differs from other genera of Pyrenulaceae by having longitudinally sulcate spores. The genus is represented by two species: S. canellae-albae (Fée) H. Harada comb. nov. and S. staurospora (Tuck.) H. Harada comb. nov. Both species have been previously reported from N. and S. America, and the latter species is now reported from Asia.

Lichenopeltella coppinsii Earland-Bennett & D. Hawksw. is described as a new species growing on Verrucaria muralis in Norfolk. It is compared with other species of the genus occurring on pyrenocarpous lichens in particular, and is close to the species informally called ‘L. hydrophila R. Sant.’, a name that has never been validly published.

Psammina inflate Earland-Bennett & D. Hawksw. and P. simplex Earland-Bennett & D. Hawksw. are described as new species from coccoid green algae and crustose or leprose lichens in lowland Britain. Additional records and hosts for P. stipitata are reported, and a key to the four species now known in the British Isles is presented. Psammina simplex is the more strongly pathogenic of the species, eventually destroying its hosts. The discovery of these new sp cies adds weight to the view that the genus is more appropriately regarded as a hyphomycete rather than an acervular coelomycete. The size, shape and septation dimensions of the conidial arms were found to be the most reliable characters for specie separations in the genus. Pycnopsammina lobariae Diederich & Etayo is also cited from the British Isles for the first time.

The genus Fenestroconidia is described to accommodate the new species Fenestroconidia caloplacae. This lichenicolous fungus produces black sporodochia, has comdiogenous cells arranged in chains, and simple, pale brown conidia with a subhyaline guttule-like zone. It is known only from central Spain (Cuenca province), growing in the apothecia of Caloplaca saxicola s.lat.

The new generic names Codonmyces and Lichenostetta are introduced for two new species of conidial fungi. Lichenostella hypotrachynae gen. et sp. nov. is a commensal of Hypotrachyna species, and is mainly characterized by forming black sporodochia with setae and, particularly, by its star-like conidia. Codonmyces lecanorae gen. et. sp. nov. occurs on Lecanora valesiaca and differs from the genus Xanthoriicola by its 1-septate conidia and campanulate conidiogenous cells with several conspicuous, flared annellations. Comments on the ecology of L. valesiaca, and its associated lichens and lichenicolous fungi are also given.

Dispersal patterns from seven terricolous lichen species, with a high capacity for asexual reproduction by fragmentation (Cetraria muricata, Cladonia species), were studied in differing vegetation types in north-eastern Germany. Marked lichen thalli were fragmented by trampling. After 15 days the spread of thallus fragments was monitored. Whereas most of the fragments that were dispersed by wind remained within a 20-cm radius from the source, the maximal dispersal distance was 57 cm in a dry sand grassland and 68 cm in an open pioneer pine forest. Dispersal was negligible in a closed old-growth pine forest. Several fragmented lichen cushions were disturbed and removed by animals, and led to a maximal dispersal distance of 9·70 m. These results suggest that: (a) thallus fragments provide good short-distance dispersal in open vegetation, but are inefficient for long-distance dispersal, and (b) wind and animals are important factors for the dispersal of thallus fragments. For restoration management of man-made substrata, artificial introduction of lichen thalli is proposed.

In boreal Scandinavia Usnea longissima is a rare epiphytic lichen associated with old spruce (Picea abies) forests. To test whether tree age was an important determinant of the occurrence and abundance of U. longissima at the scale of a forest stand we estimated thallus numbers on 1008 trees within three submontane spruce stands in south-central Norway. The stands were of all ages and multi-layered and had been selectively cut previous to the 1940s. There was no relationship between number of U. longissima thalli and tree age among trees with dbh of ≥ 10 cm. The most consistent pattern was a positive relationship between occurrence and number of thalli and stem diameter. After controlling the covariance of stem diameter, there was a tendency for a negative relationship between number of thalli and tree age. The results suggest that in old-growth resembling stands, with already established U. longissima populations, tree size (here measured as stem Diameter) is a better predictor of thallus number than tree age. This does not contradict the possibility that other environmental characteristics, associated with stands of older age, may be important for the establishment and growth of U. longissima populations.

A total of 69 species of lichens have been collected from various locations around New Zealand. Screening of extracts of these species for antimicrobial, antiviral and cytotoxic activity showed a high proportion with biological activity. Active extracts were generally from species known to contain phenolic compounds. Bioactivity-directed isolation work on Cladia retipora, Pseudocyphellaria glabra and P. homoeophylla led to the identification of usnic acid as the main antimicrobial, cytotoxic and antiviral component in these three species.