Dirina (Roccellaceae, Arthoniales) is a monophyletic genus of crustose, saxicolous or corticolous lichenized fungi. Twenty-four species are accepted in the genus, including nine new species: Dirina angolana, D. arabica, D. astridae, D. canariensis, D. indica, D. madagascariensis, D. pacifica, D. pallescens and D. sorocarpa. A phylogenetic hypothesis is presented based on data from four molecular markers, β-tubulin, ITS 1 and 2, nuLSU and RPB2, including all recognized Dirina species worldwide. New combinations proposed include Dirina badia for Roccellina badia, Dirina jamesii for Roccellina jamesii, Dirina candida for Chiodecton candidum and Dirina teichiodes for Lecidea teichiodes. Two species are reinstated: Dirina approximata and D. monothalamia (as a new name of Chiodecton africanum). Asexual morphs described earlier at the rank forma are no longer recognized as taxonomic units viz., Dirina catalinariae f. sorediata, D. insulana f. sorediata, D. massiliensis f. sorediata, D. paradoxa ssp. paradoxa f. sorediata and D. massiliensis f. aponina. One species, Dirina calcicola, is transferred to Fulvophyton and two other species, Dirina insulae-howensis and Dirina neozelandica, are transferred to Schismatomma. Dirina follmannii is not accepted in Dirina and placed as incertae sedis. A key to the species of Dirina is provided. Vicariance through plate tectonics and continental drift versus long distance dispersal to explain biogeographical patterns is discussed.

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.

Recent fieldwork carried out for the study of the lichen flora in the Upper Douro region (north-east Portugal) has resulted in a remarkable collection of Peltula specimens, including one new species (Peltula lobata J. Marques, M. Schultz & Paz-Berm.), three new species records for mainland Europe [Peltula bolanderi (Tuck.) Wetmore, Peltula farinosa Büdel and Peltula zahbruckneri (Hasse) Wetmore] and seven species new for mainland Portugal, that are reported here with a notes on their morphology and currently known distribution. The new species Peltula lobata is differentiated from any other known Peltula species by its thallus shape and size, presence of large, sessile apothecia with widely opened discs and by a complete absence of soredia. Identical specimens were also obtained from the nearby locality of Siega Verde in the province of Salamanca, and from the southern locality of Abla in the province of Almeria, both in Spain. New insights into the morphological diversity of Peltula euploca and Peltula bolanderi are also provided. The region is revealed to be a hotspot for Peltula diversity and a very promising area for further research on the morphological and molecular variation among the former species. A revised key to European species of the genus is also presented.

Four new species of lichenized fungi from northern Argentina are described and illustrated: Coenogonium albomarginatum Michlig & L. I. Ferraro, C. brasiliense L. I. Ferraro & Michlig, C. flavovirens L. I. Ferraro & Michlig, and C. verrucosum Michlig & L. I. Ferraro. In addition, C. isidiatum (G. Thor & Vězda) Lücking et al., C. magdalenae Rivas Plata, Lücking & Lizano, C. persistens (Malme) Lücking et al., C. pusillum (Mont.) Lücking et al., and C. weberi (Vězda) Lücking et al. are recorded for the first time from South America. The known distribution of 24 species of this lichen genus is extended. A revision of the genus in Argentina and Paraguay is also presented.

The diversity of pendulous Usnea species in tropical South America (Bolivia, Brazil, Colombia, Ecuador, Paraguay, Peru and Venezuela) and the Galapagos Islands is discussed with reference to 23 species. Usnea crenulata Truong & Clerc is newly described. Usnea articulata, U. deformis, U. dimorpha, U. geissleriana, U. merrillii, U. perhispidella, U. sanctaeritae, U. subflammea and U. transitoria are newly reported for South America. Modern descriptions are provided for Usnea amabilis, U. arthroclada, U. dodgei, U. humboldtii and U. regia. We propose to reject the synonymy of U. hesperina with U. schadenbergiana, and the valid name for U. hesperina is therefore U. subgracilis. Distinct patterns of unidentified triterpenoids have been detected by thin-layer chromatography and are used to characterize several species within this group. The morphology, branch anatomy, chemistry, ecology and distribution of each species are given, together with an identification key.

Five new species of the genus Polymeridium are described from Brazil. All exhibit at least one character that was previously unknown in the genus: P. corticatum has a corticate thallus and 2 ascospores per ascus, P. immersum has the ascomata deeply immersed in the bark under the thallus, P. isohypocrellinum has a red, KOH+ green pigment (iso-hypocrellin) in the ostiole, P. julelloides has short and broad muriform (Julella-like) ascospores, and P. paraproponens has ascomata in groups of two to three. Brazil is clearly the centre of diversity of the genus. Iso-hypocrellin is a new substance for the genus.

The new species Oropogon evernicus Essl. & S. Leavitt and O. protocetraricus S. Leavitt & Essl. are described from montane regions of Central America, further increasing the diversity of this genus in the New World. Oropogon evernicus is separated from O. americanus by the presence of medullary tissue directly beneath the pseudocyphellae, while O. protocetraricus is separated from O. caespitosus by the presence of protocetraric acid. The segregation of both species is confirmed by molecular sequence data (nuclear ITS, nuLSU, and β-tubulin). Both species appear to have split from their most recent common ancestor during the Miocene, supporting Miocene-dominated diversification of neotropical Oropogon species found in Central America.

A quantitative cluster analysis of lichen distribution data demonstrates that the main biogeographical subdivision in the world's lichen biota is into a Gondwanan and a Laurasian element. Patterns at smaller scales mainly reflect local climate. Wallace's line is not a significant boundary for lichens. The Gondwana / Laurasia split also applies to lichenicolous fungi. To a considerable extent, it applies to many of the larger families and orders of lichens too, though at these ranks the affinities of the lichen biota of eastern Asia and temperate North America are sometimes ambiguous.