Two lichenicolous species are discussed: the recently described Unguiculariopsis nephromae, which occurs on Nephroma species in Canada, Fennoscandia, North America and Russia, is combined into Protounguicularia; and Hyalopeziza rapax sp. nov. is described from Pseudocyphellariacrocata in Alaska. In discussing generic placements, it is concluded that the species now known as Olla transiens is better accommodated in Protounguicularia and the species is combined into that genus. Attention is drawn to variability in general appearance of P. nephromatis, particularly the occurrence of both superficial and erumpent apothecia in the same species.

The taxonomic and nomenclatural status of the common Scutula (Ramalinaceae, Lecanorales, Ascomycota) parasitizing species of Solorina (Peltigeraceae, Lecanorales) is clarified. The type of Biatorina tuberculosa Th. Fr., which, according to the protologue, was described from a Peltigera, is actually growing on Solorina saccata, and the correct name for this species is here shown to be Scutula tuberculosa (Th. Fr.) Rehm. Lectotypes are designated for Lecidea solorinaria Nyl., Scutula krempelhuberi Körb. and Lecidea solorinicola Vain. Notes on the taxonomy and classification of the genus are given, and a key to the species of Scutula s. str. in the Northern Hemisphere is presented. Scutula tuberculosa is reported as new to Asia and North America.

The new fungus Cercidospora alpina is described from Sweden where it grows on the thallus of the crustose lichen Stereocaulon cumulatum. The ecology and distribution of the new species as well as its morphological similarities to related species are discussed. A key to the known species of Cercidospora occurring in Fennoscandia is provided.

While studying the taxonomy of the non-yellow species of Rhizocarpon DC., with hyaline and muriform ascospores, in the Nordic countries (Ihlen 2004), some specimens of Rhizocarpon from the Svalbard archipelago were also examined. Among this material, we discovered six specimens of Rhizocarpon anaperum (Vain.) Vain. that had been labelled “R. obscuratum”. As R. anaperum is not listed in the recent checklist from Svalbard (Elvebakk & Hertel 1996) or, to our knowledge, in any other paper dealing with the lichen flora of Svalbard, it is here reported new to this archipelago.

The taxonomy of the non-yellow species of the genus Rhizocarpon (Rhizocarpaceae, lichenized Ascomycota) occurring in the Nordic countries, with hyaline and muriform ascospores, has been revised. Rhizocarpon amphibium, R. anaperum, R. distinctum, R. furfurosum, R. lavatum, R. petraeum, R. postumum, R. reductum, R. roridulum, R. rubescens, R. subgeminatum, R. sublavatum (reported from the study area for the first time), R. subpostumum, R. suomiense, R. timdalii, and R. umbilicatum are recognized. Their morphology, anatomy, secondary chemistry, ecology, and distribution in the Nordic countries are investigated and discussed. Distribution maps and a key to the species are provided. The most important characters for separating the treated species are pruinose/epruinose thallus, number of ascospores in asci, ascospore size and number of cells per ascospore in optical view, insoluble lichen pigments of the epihymenium and the proper excipulum, and lichen substances. Seven names are lectotypified and two are neotypified.

The new lichenicolous species Lichenostigma supertegentis is described from Sweden and Norway where it grows on thalli and apothecia of Aspicilia supertegens. The ecology and distribution of the new species are discussed and a distribution map is provided. The concept of Lichenostigma is enlarged to accommodate fungi producing macroconidia.

The new species Rhizocarpon timdalii, is described from north-west Europe and north-east North America. The ecology and distribution of the new species are also discussed.

Epiphytic lichens (and some non-lichenizedfungi) on 34 coppices (204 stems) of Corylus avellana were investigated in a 140 ha study area in south-western Norway. A total of 65 species were recorded on a total bark area of 63 m⊃2. Corylus in broad-leaved deciduous forest supported more species of macrolichens, and fewer species of microlichens, than Corylus in pine forest. The macrolichen flora of the deciduous forest differed from that of the pine forest by having a rich flora of species belonging to the Lobarion alliance. Old Corylus coppices with tall stems (>8 m), large girth (>8cm diameter at breast height) and a noticeable cover of macrolichens (>10% of bark area) supported the highest number of rare species, and overall, species of macrolichens. More than 50% cover of microlichens indicated richness and rarity of microlichens on Corylus. 11 2001 The British Lichen Society