Recent revisions of generic relationships in the pyrenocarpous lichen family Trichotheliaceae by J. Hafellner & K. Kalb (based on perithecial pigmentation and ascus structure) and R. C. Harris (based on morphological, chemical and environmental trends) are assessed. However, most of their conclusions are rejected because the authors used shared or variable characters, insufficient specimens and highly disjointed groups of species.

Caloplaca maritime B. de Lesd. is a marine to maritime species occurring in western Europe. It was first described as a variety of C. citrina (Hoffm.) Th. Fr., but in 1953 was transferred to specific level. Since then C. maritima has been more or less forgotten and/or misunderstood, mainly due to confusion with C. ruderum(Malbr.) J. R. Laundon, C. interfulges (Nyl.) J. Steiner, and C. marina (Wedd.) Zahlbr. The present paper reports on the existence of C. maritima, and clarifies its status in relation to C. marina and to other related species. A map of the presently known distribution is presented and the species is depicted. Lectotypes for Caloplaca citrine var. maritime and C. citrine var. maritime f. laevigata are selected.

A new lichenicolous fungus species, Polydesmia lichenis Huhtinen & R. Sant., growing on species of Peltigera is described from Sweden and Norway.

The genus Lecanactis, with 24 species, has been phylogenetically analysed using cladistic parsimony methods and support tests. Morphological, anatomical and chemical data were used, comprising 38 characters. Twelve equally most parsimonious trees were obtained. The successive approximations character weighting method gave one most parsimonious tree. The ingroup, Lecanactis, is supported as monophyletic. Although parsimony jackknifing and Bremer support indicate that the trees are poorly supported, some groups are wholly or partly distinguished in both the strict consensus tree, the successive weighting tree and the Jac tree.

Thirteen species of the lichen genus Sticta (Schreber) Ach., are recognized in the New Zealand flora viz.: S. babingtonii, S. caliginosa, S. colinii sp. nov., S. cinereoglauca, S. filix, S. fuliginosa, S. lacera, S. latifrons, S. limbata, S. martinii, S. squamata, S. subcaperata and S. sublimbata. A key to species, synonymy and typification, descriptions of all taxa, biogeographical affinities and distribution maps are presented. Sticta livida is excluded from the New Zealand flora.

A set of artificial keys is presented to all those crustose lichens (except most species of Lepraria and Leprolomd) which commonly occur without fruiting bodies on rock or soil in the British Isles. A number of predominantly corticolous species that occasionally also occur on rocks are included, as well as several undescribed but well-understood entities.

Usnea quercina Bystrek & Gòrzynska, based on heterogeneous type material, is lectotypified and becomes a synonym of U. wirthii P. Clerc. Usnea wirthii is new for South America. A distribution map of U. madeirensis Motyka (Syn. U. silesiaca Motyka) in Europe is given. Usnea hesperina Motyka (Syn. U. elongate Motyka, U. schadenbergiana Göpp & Stein, U. subgracilis Vain., U. subplicata (Vain.) Motyka) is new for Africa, Asia and South America. Usnea hirta (L.) F. H. Wigg. (Syn. U. corrugate Motyka, U. foveata Vain., U. leprosa Motyka) is new for Africa. Usnea subscabrosa Nyl. ex Motyka (Syn. U. santae-annae Motyka) is new for South America. The holotype of U. marocana Motyka (=U. mutabilis Stirt.) was found in LBL.

Arhothelium saxicolum Makhija & Patwardhan sp. nov. is described from India. It occurs abundantly only on basaltic rock and is restricted to the northern parts of Western Ghats, South-West India.

The saxicolous Strigula fractans sp. nov. and S. rupestris sp. now are described from Lord Howe Island, New South Wales, Australia. A new combination, S. decipiens (Malme) P. M. McCarthy, is proposed for Porina decipiens Malme, and a key to the 17 saxicolous species of Strigula is provided.

Protoparmelia hypotremella van Herk, Spier & Wirth, a sterile corticolous lichen, is described as a species new to science, so far known from Austria, SW Germany and the Netherlands. It is rapidly spreading in Germany and the Netherlands. It is apparently close to P. oleagina, and is often found growing together with that species on oak trees along roads in the Netherlands. Both species are host to the lichenicolous fungi Sphinctrina anglica and Tremella wirthii.

Lepraria eburnea is shown to comprise three morphologically indistinguishable chemotypes, containing either protocetraric acid, psoromic acid, or neither substance, in addition to alectorialic acid. The holotype of L. frigida contains protocetraric acid and alectorialic acid, and is thus united with L. ebumea under the latter name.

Strigula macaronesica Sèrus., a new foliicolous species found in Madeira and Gomera, is distinguished by its almost linear thallus growing along leaf margins or scars and by its unusually small obclavate asci.

Trichothelium argenteum R. Lücking & L. I. Ferraro sp. nov. is distinguished by its very large perithecia with a well-developed, silvery white, basally black crown of setae, and by a non-radiate phycobiont. In young perithecia, the setae are confluent and form a characteristic, two-coloured disc-like expansion. Ascospores are 7-septate and bacillar. Trichothelium argenteum is known from a few populations in Costa Rica, Ecuador, Brazil, Paraguay, and Argentina.

Xanthoria poeltii, a new species combining characters of X. candelaria and X. ulophyllodes from Sweden, Denmark, Germany and Hungary, is described and illustrated. Comments about its differences from related taxa are provided.

Belonia mediterranea Nav.-Ros. & Llimona sp. nov. is described and compared with other, mainly saxicolous, species of the genus. It is known only from the type locality, Medes Islands (Catalonia, NE Spain), where it occurs on shaded limestone cliffs, near the Mediterranean seashore. It differs from related saxicolous species of Belonia mainly in the appearance of the thallus, ascospore septation and ecology. A key to the European species of Belonia is provided.

Melaspilea circumserpens Nyl., hitherto known only from the type specimen, collected in Tasmania in 1803 by Robert Brown, has been rediscovered. The species has proved to belong to the genus Glonium (Hysteriaceac), previously not known to contain species associated with algae. The new combination Glonium circumserpens (Nyl.) Kantvilas & Coppins is proposed. The anatomy, morphology and ecology of the species are described. Problems regarding the provenance of several lichen specimens collected by Robert Brown are discussed.

The monotypic genus Botryolepraria Canals et al. is described. The type species, B. lesdainii (Hue) Canals et al. is a sterile, cottony, pale green lichen, made of hyphae supporting subterminal bunches of chlorophycean algae.

Two corticolous species of the lichen genus Xanthoria, X. alfredi S. Kondratyuk & Poelt from Russian and Chinese Far East and X. aphrodites Kalb, Poelt & S. Kondratyuk from Cyprus are described. Morphological characters, in particular the presence of true rhizines within Xanthoria and their differences from hapters are indicated. Xanthoria novozelandica Hillmann is the first species of Xanthoria in which oil paraphyses have been found. A key to the treated species, including X. novozelandica and Xanthoria sp. from western North America is provided. The ecology and distribution of described species are discussed. Xanthoria alfredi and X. ulophyllodes probably constitute a typical species pair; X. alfredi and X. aphrodites are relict endemics.

Two new species of Xanthoria are described and illustrated, and comments about their differences from related taxa are provided. These are: X. ascendens from bark and shrub remains in sea-shore sand dunes and hillsides in Argentina, Chile and Peru, and X. ucrainica, from bark, stones, and some man-made substrata in the Ukraine, Sweden, United Kingdom, Germany, Austria and Asian Russia.

The anatomy and chemistry of Lecanora vacillans H. Magn. has been studied. This saxicolous species combines key characters of both the L. subfusca and L. subcarnea groups and indicates that the representative groups should not be segregated at generic level. More particularly L. vacillans resembles the L. subfusca group in its apothecial anatomy but contains chemical substances typical of the L. subcamea group, whereas the morphology is reminiscent of both groups. Lecanora vacillans f. infuscate is reduced to synonymy with L. vacillans.