Three new species of Diploicia are described from the Galapagos Islands and a fourth, D. glebosa, is transferred from Pyxine; all four are considered endemic to the archipelago. In order to accommodate these species, the generic concept of Diploicia has been emended. Two of the species are sterile; D. leproidica is placodioid-leproid, where the thalli derive from pseudocorticate granules aggregating into small, placodioid rosettes with distinctly lobate margins. The second sterile species, D. squamulosa, forms scattered squamules that eventually aggregate into small, placodioid rosettes. The two fertile species, D. glebosa, with an olivaceous to beige, smooth, epruinose upper surface, and D. neotropica, with a white to grey-white, roughened, pruinose upper surface, form larger thalli typical of Diploicia, have apothecia that are initially lecideine, but are soon engulfed and hidden by a thick thalline margin. Anatomically the proper exciple remains visible for a considerable part of the ontogeny, although it eventually becomes almost completely reduced to a few pigmented or almost hyaline hyphae. This transition from lecideine to lecanorine apothecia is similar to the physciaeformis-type ontogeny observed in some Pyxine species. Several species currently accommodated in Buellia s. lat. with diploicin and effigurate thalli that lack distinctly lobate margins are discussed and the Socotran endemic Physcia endopyxinea is transferred into Diploicia.

Amandinea lobarica, a new corticolous lichen species, is described from high elevations in Guatemala. It is characterized by a thin, granulose, brownish thallus containing lobaric acid, small, convex lecideine apothecia, filiform conidia and large, narrowly ellipsoid ascospores with roughly ornamented walls. The new species is compared with other Buellia s. lat. taxa that possess rather large and strongly ornamented ascospores, such as Buellia hypothallina, here placed in synonymy with Gassicurtia vaccinii, Amandinea leucomela, A. mediospora, A. megaspora, A. subduplicata and five very closely related taxa treated here as belonging to the Amandinea incrustans group. Two tables summarizing the main differences between these species and a key are provided. New data on the chemistry of A. leucomela and a new record of A. montana for Guatemala are also included.

Buellia subericola, a new corticolous species characterized by a brown, blastidiate thallus without secondary chemistry and triseptate to occasionally submuriform ascospores, is described from the southern Iberian Peninsula. The species occurs on Quercus suber in grass-woodlands of cork-oak in the mesomediterranean belt with a warm mediterranean climate and oceanic influence. It is compared with other known Buellia s. lat. taxa which also reproduce asexually and have similar ascospores.

The study of the type and additional material of Buellia andicola, B. hypophana and B. reagens has shown that these taxa are conspecific with B. thiopoliza. Buellia thiopoliza is a muscicolous species growing at middle to high altitudes in the mountains of both hemispheres. It is easily recognized by its K+ purple-red yellow pigment mainly concentrated in the hypothecium, and by the presence of xanthones in the thallus and the apothecial tissues. The new combination Tetramelas thiopolizus is proposed. A key to all known Tetramelas species is included. The also muscicolous Buellia hypoleuca is reduced to synonymy with Phaeorrhiza sareptana var. sphaerocarpa.

Amandinea myrticola is described as new from Portugal. This corticolous species is characterized by the thin, smooth to minutely rugose and greyish thallus lacking secondary metabolites, the small lecideine apothecia which exhibit a pseudothalline margin when young and the small, smooth, Physconia-type ascospores with strongly pronounced and persistent median wall thickenings. It occurs on smooth bark in two localities characterized by a Mediterranean climate with an Atlantic influence.

Well-developed ascospores of Rinodina flavosoralifera have been observed for the first time. The ascospores are described and illustrated and new data on the chemistry and distribution of this species are provided. New chorological data on Rinodina disjuncta are also included.

Buellia rhizocarpica is described from Mexico. This corticolous species is characterized by a yellowish, granulose thallus, the presence of rhizocarpic acid and an unknown pulvinic acid derivative, apothecia containing large amounts of micromera-green together with yellow crystals which react K+ pinkish and by the presence of very small, Buellia-type ascospores. It grows in a well-preserved Pinus hartwegii forest at c. 4000 m altitude at the base of the volcano Popocatepetl.

Buellia nordinii, a new muscicolous or lignicolous species characterized by a blastidiate thallus containing atranorin, apothecia with a fine granular surface, markedly enlarged paraphyses tips and large triseptate ascospores is described from Venezuela. The species grows in very humid situations near the ground in open paramo vegetation at high elevations. It is compared with other known asexually reproducing and triseptate Buellia taxa.

Rinodina fuscoisidiata, a muscicolous isidiate species with large isidia and Pachysporaria-type ascospores is described from Venezuela. This species contains an unknown terpene as a major secondary metabolite in addition to traces of atranorin. It is compared with the four known isidiate Rinodina taxa.

Rinodina brasiliensis, a corticolous isidiate species with large Pachysporaria-type ascospores is described from south-eastern Brazil. The new species is closely related to R. dolichospora and to R. guianensis.Rinodina confinis is a synonym of R. dolichospora. Notes on the taxonomy, morphology, anatomy, chemistry and distribution of these three taxa are given. Descriptions and iconography are provided. A key to species is also included.

The silicicolous lichen species, Rinodina etayoi Giralt & van den Boom, is described as new from inland localities of Fuerteventura and Lanzarote (Canary Islands). It is characterized by a crustose, whitish thallus containing atranorin, zeorin, chloroatranorin and stictic acid, hemispheric pseudolecanorine apothecia containing, a proper exciple inspersed with numerous and large oil drops, and by ascospores of the Mischoblastia-type. The joint occurrence of pannarin, stictic acid and Mischoblastia-type ascospores makes R. etayoi unique within the genus.

Examination of Rinodina specimens from the Cape Verde Islands revealed three new species, which are described here: Rinodina capeverdeana Giralt & van den Boom, R. inspersoparietata Giralt & van den Boom and R. polymorphaespora Giralt & van den Boom. Additional information is given for six further species, of which five are new records for the archipelago. Rinodina punctosorediata Aptroot & Sparrius was found to be conspecific with R. stictica Sheard & Tønsberg.

The morphology, anatomy, ecology and distribution of Buellia tesserata and Dimelaena radiata are discussed. New data on their chemistry are given. The present study reveals a very close relationship between both taxa and consequently their different generic position is questioned. Buellia fimbriata is reduced to synonymy with Buellia tesserata.

A new corticolous species of Buellia is described from La Palma and La Gomera (Canary Islands). It is mainly characterized by its strongly ornamented, (l-2)-3-septate ascospores with apical and septa thickenings, which follow an ascospore-ontogeny of type B, and its chemistry. The new species is compared with the related Buellia lauricassiae (Fée) Mü. Arg. and B. lauricassiaeoides Aptroot. Illustrations of the ascospores of B. laurocanariensis and B. lauricassiaeoides are presented. A habit photograph of the new species is also provided.

Iberian records of Buellia triseptata A. Nordin are presented. This corticolous and lignicolous species was recently described from North America. A description based on the Iberian material is given, together with notes on ecology and distribution. Specimens belonging to B. triseptata were previously reported as B. disciformis, B. lauricassiae, B. pharcidia and B. triphragmia. The main distinguishing features between these taxa and B. triseptata are pointed out, and background to the misapplied names is given. Illustrations of the ascospores of B. triseptata and B. lauricassiae are presented. A distribution map of B. triseptata in the Iberian Peninsula is also provided.

A description of the polysporous Buellia dives (Th. Fr.) Th. Fr. is provided. It is distinct from Buellia polysporella (Nyl.) Arnold, with which it has been placed in synonomy, by the lecideine (versus lecanorine) apothecia, the dark brown (versus colourless) hypothecium and the Buellia-type (versus Physcia-type) ascospores. Further, B. polysporella is shown to be conspecific with Rinodina polyspora Th. Fr. and is reduced to synonomy with that species. Buellia dives is reported as new to Norway and Spain and notes on its ecology and distribution are given.

Amandinea crassiuscula Giralt & Etayo, a new corticolous lichen species is described from the Iberian Peninsula. It is characterized by a thickly crustose to subsquamulose thallus that lacks secondary lichen compounds, lecideine apothecia, Buellia–type ascospores with rugulate ornamentation and filiform spermatia. The new species is compared with other corticolous Amandinea and Buellia species, such as A. punctata and B. chloroleuca. Habit photographs of the new species and illustrations of its thallus, spermatia and ascospores are also provided.

The study of the type material of Buellia ericina (Nyl.) Jatta has revealed that this species is characterized by the same diagnostic characters as Rinodina madeirensis Kalb & Hafellner, and both taxa are here considered to be conspecific. The generic position of Buellia ericina is discussed and it is concluded that the species is better placed within the genus Rinodina (Ach.) Gray. New chemical data on this taxon are provided, and its sorediate variety, R. ericina var. boomii, is described as new from Portugal. Its closest affinities are shown to be with Rinodina kalbii Giralt & Matzer and probably also R. insularis (Arnold) Hafellner.This group stands apart in the family Physciaceae. It shows affinities with Diploicia A. Massal. and is included provisionally in Rinodina.

The morphology, anatomy, chemistry and ecology of some corticolous and lignicolous species of Buellia from the Iberian Peninsula that contain secondary lichen compounds are discussed, including B. chloroleuca, B. disciformis, B. erubescens, B. hyperbolica and B. leptoclinoides. These species are compared with other corticolous Buellia species that occur outside the study area, including B. arnoldii, B. insignis, B. regularis and B. sanguinolenta. The misunderstood B. zahlbruckneri J. Steiner and B. jorgei, are synonyms of B. erubescens, and the invalid taxon B. zahlbruckneri sensu Schauer non Steiner and B. poeltii, are synonyms of B. chloroleuca. New chemical data on several taxa are reported. A key to the pecies and illustrations of their ascospores are provided.