Zwackhiomyces cervinae Calat., Triebel & Pérez-Ortega is described as new to science from Spain and Iran. This lichenicolous species grows on the lateral side of the squamules of Acarospora cervina, and it is characterized by its relatively large ascospores, which are brown when overmature. It is compared with several Zwackhiomyces species and with other taxa sharing some of its characters. A key to all the known species of the genus is also provided.

The lichenicolous hyphomycete Taeniolella diederichiana Etayo & Calatayud, is described from the Andes (Colombia and Peru) and the Canary Islands. It grows on the thallus and apothecial margin of Placopsis. It is characterized by forming minute sporodochia over a basal group of polyhedral cells, and by its conidia with a verruculose to verrucose-striate wall.

Lichenostigma radicans Calat. & Barreno, a lichenicolous fungus growing on vagrant Aspicilia species, is described as new to science from Spain. It is superficially similar to L. maureri, with cushion-like ascomata, but differing mainly by its ascomata connected at their base to immersed, brown, vegetative hyphae. Comments on the variability of iodine reactions of asci and ascospore walls, and on an associated conidial fungus with small bacilliform conidia, are given for L. maureri.

Comments on and a key to the 13 Polycoccum species known in Spain are presented, including synopses of their world distributions. Amongst these is P. rubellianae sp. nov., a lichenicolous fungus growing on thalli of Caloplaca rubelliana in eastern Spain (Valencia). It has relatively small ascomata, the lower part pale brown, and also small ascospores which are coarsely verrucose and have a thick gelatinous sheath when young. The new species is associated with a Phoma-like anamorph. The identity and systematic position of P. opulentum requires further study as the name has been applied to different species, and the occurrence of P. marmoratum in Spain is in need of confirmation. The Spanish record of P. arnoldii on Lecania cyrtella probably refers to another yet undescribed species.

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.

Stigmidium cartilagineae Calatayud &Triebel (on the apothecial discs of Squamarina cartilaginea), a lichenicolous fungus belonging to Stigmidium s. str., is described as new. Two other species of Stigmidium s. 1. with a net of branched and anastomosing, rudimentary interascal filaments are also described as new to science: Stigmidium rouxianum Calatayud & Triebel (on Acarospora cervina) and S. squamarinicola Calatayud & Triebel (on the thallus of Squamarina spp.). They are related to Stigmidium psorae and treated here as ‘Stigmidium’ psorae group. To facilitate discussion of the distinguishing features of this group, a table comparing the terms referring to hamathecial hyphae in pyrenocarpous ascomycetes is presented.

A synopsis of the subgenus of lichenicolous fungi Lichenogramma is presented. It comprises eight species of Lichenostigma with oval to elongate ascomata connected to superficial strands of vegetative hyphae. Five of them are described here as new: Lichenostigma diploiciae (on Diploicia subcanescens); L. epipolina (on Diplotomma epipolium); L. gracilis (on Acarospora fuscata); L. rouxii (on Squamarina spp.); and L. subradians (on Acarospora spp., mainly subgen. Acarospora). The concept of the genus Lichenostigma is enlarged to accommodate also species with submuriform ascospores. A key to all the species of the subgenus is provided.

The new genus Lichenopyrenis is described for L. galligena, a cecidiogenous species parasitic on the lichen Leptochidium albociliatum. This genus is characterized by perithecioid ascomata with a cellular wall, formed by relatively large, somewhat compressed cells, fissitunicate, I- asci, wide hamathecium filaments, and 1-septate, pale orange brown ascospores with distoseptate thickenings which at maturity are seemingly bulging out of the exospore wall at the septum and apices. The conidia have a rhexolytic type of secession, and are attached to the conidiogenous cells by a separating cell. Lichenopyrenis is referred tentatively to the family Pleomassariaceae.

A taxonomic and ecological reassessment of the genus Cresporhaphis is presented, with a key to all 7 species currently known, including C. ulmi sp. nov. from Spain, on twigs of Ulmus minor. Species are facultatively lichenized with chlorococcoid algae, Trentepohlia and other algae, or saprobic.

Lecanora herteliana is described from several collections from hard siliceous sandstone, in typically Mediterranean habitats in eastern Spain. The new species has a whitish thallus containing atranorin and norstictic acid. Its apothecia are mostly black, with a thalline exciple, which is finally excluded, and with a well developed true exciple.Lecanora herteliana is most closely related to L. subcoarctata, and it is discussed in relation to this species and other members of the L. marginata group.

Lichenochora mediterraneae Calatayud, Nav.-Ros & E. Calvo (Phyllachorales)a new species of non-lichenized lichenicolous fungi, is described from the provinces of Cádiz and León (Spain)growing on Fuscopannaria mediterranea. is mainly characterised by having bispored asci, and 3–4-septate, narrowly cylindrical or bacilliform spores. The new species is compared with L. clauzadei and L. bellemerei, the two previously known species with pluriseptate spores.

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.

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 influence on uptake and water loss of the structural changes experienced by Parmelia acetabulum during thallus development were investigated. Small specimens were characterized by flat lobes and a thin thallus and cortex. Large specimens appeared strongly rugose, imbricate and irregularly folded, and had a significantly thicker cortex and medulla than small thalli. Maximum water storage capacity did not differ between large and small thalli, although water retention was much higher in large thalli, presumably due to the interaction of structural characteristics and a higher boundary layer resistance. This translated into a longer duration of the period of thallus hydration in large thalli compared to small thalli. Incubation of thalli in water-vapour-saturated atmospheres induced full recovery of photosynthetic electron transport to the values before desiccation in small thalli but only induced a partial recovery in large thalli. The close correlation between photosynthetic electron transport and net photosynthesis during desiccation found in this species suggested that carbon-fixation activity could be regained to a larger extent by incubation of thalli in water vapour in small compared to large thalli. The higher ability for water vapour uptake of small thalli might allow them to efficiently use small amounts of intermittently available water or periods of high relative humidity. The significance of this differential ability to utilize water is discussed with regard to the known ecological preferences of the species.