Thallus organization is examined in Aspicilia californica Rosentreter, fruticose lichen known from several localities in central and southern California. The sprawling, terete thallus branches possess a dense central medulla of thickwalled, longitudinally oriented fungal cells. This central tissue emerges at branch apices to form a darkly pigmented fungal tip. Thallus development involves the apical extension of the tip to produce a fungal tissue over which a cylindrical algal layer and cortex will eventually be formed. Apical branches are initiated by furcation entirely within the fungal tip. Lateral branches, emerging from the lichenized thallus, arise as a divergent bundle of elongate fungal cells originating in the medulla. The photobiont appears to play no direct role in initiation of apical or lateral branches. It is concluded that thallus development in A. californica occurs with a relatively low degree of synchrony between mycobiont and photobiont growth, similar to the pattern observed in crustose lichens with prothallic growth. A rather similar type of thallus organization is observed in A. hispida, although in that species mycobiont growth and branch initiation appear to be somewhat more closely associated with algal cell proliferation. A squamulose Aspicilia from central Spain produces rhizomorphs that may sometimes become invested with an algal layer and cortex, resembling the thallus axes of A. californica.

Bryona tortuosa is reported as new to northern Europe. Notes on its morphology, chemistry, ecology and distribution are given and the distinction from its closest ally, B. fremontii, is discussed.

Lecania poeltii v.d. Boom, Alonso & Egea sp. nov. is described from Portugal and northern Africa. The species is characterized by its inconspicuous hairs on thallus and apothecia, in which it differs from the other known species of the genus.

Thermutopsis jamesii Henssen gen. et sp. nov. (Lichinaceae) is described from calcareous rocks in Antigua. The new species resembles in habit Thermutis velutina but differs in the internal stucture and development of thallus and fructifications. The cyanobiont is a poorly lichenized species of Tolypothrix; the fructifications arise within the the gelatinous sheath of the algal filaments. The ascocarps are thallinocarps of a special type; the hymenium stains deep blue in iodine; young paraphyses are thick and richly branched; the prototunicate, non-amyloid asci contain 8 simple, colourless spores. The pycnidia are ellipsoid, producing small rod-shaped, acrogenous conidia.

The type species of Squamarina has two varieties, S. gypsacea var. gypsacea and S. gypsacea var. subcetrarioides. In this study, a phylogenetic and taxonomic analysis of these two varieties shows that S. var. subcetrarioides merits treatment as a species separate from S. gypsacea. Therefore, we raise this variety to species level as S. subcetrarioides (Zahlbr.) Y. Y. Zhang. Squamarina subcetrarioides is phylogenetically not closely related to S. gypsacea and differs from that species in the thallus forming rosettes when young, later becoming cracked and irregular in outline, and consisting of numerous small squamules.

This study re-examined the status of species of Diorygma Eshw. known from the Western Ghats using an integrative taxonomy approach that includes morphological and chemical data, as well as multigene phylogenetic analyses. Prior to this work, the two species D. karnatakense and D. dandeliense were distinguished primarily on lirellae morphology (branching pattern) and the number of ascospores per ascus. Our study of the morphology, chemistry and molecular phylogeny (mtSSU, LSU and RPB2) of freshly collected samples and re-examination of type material suggests that both names should be synonymized. Consequently, D. karnatakense is accepted as the correct name, with D. dandeliense as a newly proposed synonym. Phylogenetically, D. karnatakense is allied to D. antillarum and D. hieroglyphicum.

The production of anthraquinones is a major characteristic of most species in the Teloschistaceae. Other secondary metabolites are quite rare in this family, but some species are known to produce depsides, depsidones, xanthones and usnic acid. A new monotypic genus, Neoplaca, with a new species N. mirabilis, is described from the subfamily Caloplacoideae of the family Teloschistaceae, lacking anthraquinones but containing the naphthopyrans simonyellin and consimonyellin. This is the first time this class of organic compounds has been found in the family Teloschistaceae and the second in the order Teloschistales, where simonyellin has been detected in Brigantiaeaceae. Simonyellin and consimonyellin have also previously been reported in the family Roccellaceae. Neoplaca mirabilis is currently known from the two nearby localities in Yakutia, Russia, where it is common and grows on base-rich soil on exposed south-facing siliceous outcrops. The thallus consists of scattered whitish to greyish, or rarely with pale yellow tinge, squamules 1–4.5 mm diam. and 0.3–1 mm thick with citrine to orange-yellow blastidia produced from their margin; apothecia and pycnidia are unknown. In addition to naphthopyrans, N. mirabilis contains an unidentified brown pigment similar in some features to melanin. The new species is also interesting in that the pigments are apparently located inside the cells of the cortex, not on their surface, where anthraquinones are found in Teloschistaceae.

During a visit to the Natural History Museum London I examined material of the genus Porocyphus from the British Isles. A collection labelled Porocyphus coccodes [Scotland, Forfar, Caenlochan, on damp, E-facing rock (±basic), 1700 ft, 10 viii 1968, P. James (BM)] turned out to be a well-developed specimen of Metamelanea umbonata Henssen. Another two specimens from Scotland sent to me for identification belong here as well: Mid-Perth, Bread-albana, Creag Mhòr, S-facing cliffs, 700–800 m, 27/39.35, 6 vii 1979, B. Coppins 4573 (E, hb M. Schultz); Angus, Caenlochan Glen (N side), Glasallt Burn, W-facing cliffs, on vertical flushed granite cliff face, 800 m, 37/17, 7 viii 1989, B. Coppins 13383 & O. Gilbert (E, hb M. Schultz).