The morphology and the anatomy of the 13 species presently included in the genus Fulgensia were surveyed. Caloplaca aurea and C. paulii, two speciesregarded as closely related to Fulgensia by earlier authors, were also included in the study. Fulgensia was found to exhibit a great variation in both morphology and anatomy. The differences in size, shape and septation of the spores, in the anatomy of cortex and exciple, and in the gross morphology, will presumably motivate a different taxonomic treatment in the future. A tentative separation of the species into four different groups is proposed here. Group A comprises F. australis and F. chanousiae, which appear close to species in Caloplaca sect. Gasparrinia. Groups B and C, each comprises one species, F. schistidii and F. canariensis respectively and group D comprises the remaining nine species, including the type species F. fulgens. The last group may be further split by a more detailed investigation. The present separation of Fulgensia into two subgenera cannot be regarded as taxonomically sound. The genus is probably polyphyletic and the different groups are probably related to different groups within the large genus Caloplaca.

Two Parmeliella-like lichen species are described as new: Santessoniella pulchella, known from warm temperate parts of eastern Australia and northern New Zealand, and Siphulastrum squamosum, a relatively common species on stumps ofNothofagus in southern Chile. Both differ from Parmeliella s. str. in the hemiamyloid, finally red-brown hymenial iodine reaction and the apical structures of the asci, as well as in thallus details (anatomy and chemistry). Parmeliella major Darb. is a synonym of P. thysanota (Sirt.) Zahlbr., which thus proves to be a circumpolar species in the Southern Hemisphere, though not yet discovered in South Africa. A new species, Parmeliella lacerate, is described from the Republic of South Africa, and related to Parmeliella chilensis (Hue) P. M. Jørg., comb. nov.

Gyalideopsis cochlerifer Lücking & Sérus. sp. nov. is a new, pantropical, commensalistic species restricted to foliicolous representatives of certain genera in the Gomphillaceae. It produces black spathulate hyphophores and small black apothecia.

The new species, Polysponna terricola Kantvilas from south-eastern Tasmania, is described and compared to other species in the genus. It is well characterized by a range of morphological, anatomical and ecological characters, especially by the presence of oil paraphyses and oil droplets in the hymenium, features unknown in other members of the genus. Species of Polysporina are best separated by the following characters: size and morphology of the apothecia, size of ascospores, thickness of paraphyses and height of the hymenium. The combinations P. ferniginea (Lettau) M. Steiner and P. pusilla (Anzi) M. Steiner are validated. A key to the taxa studied is provided.

Belonia pellucida sp. nov. is described from coastal scrubland in North Island, New Zealand. This is the third report of the genus Belonia(Gyalectales) from the Southern Hemisphere. Belonia mediterranea is reported for the second time, from Mallorca.

Morphogenesis of podetia in Cladonia subcervicornis is a non-linear, repeating process based upon a pattern of meristem enlargement and division. Variability in mature podetia of C. subcervicornis, which may appear branched or scyphoid, is the result of variation early in ontogeny. The growth pattern of C. subcervicornis represents a continuum of developmental stages. It is impossible to predict the form of the mature thallus of C. subcervicornis because growth in this species is fluid. The morphology of the mature thallus of C. subcervicornis is difficult to circumscribe using conventional Cladonia terminology, because the processes that form the thallus are dynamic and heterogeneous. The meristem shapes that are produced during early ontogeny in C. subcervicornis are relatively simple, and the processes by which they are formed are uncomplicated. Yet podetial form in C.subcercicornis is difficult to interpret.

The quantitative response to two lichen metabolites, vulpinic acid and (+) usnic acid, on biomass production by the photobiont Trebouxia irregularis, isolated from the lichen Cladina mitis, was determined experimentally. The presence of usnic acid resulted in inhibition of photobiont growth, and the effect depended on the pH of the culture medium. The concentration effect of usnic acid was observed. The application of vulpinic acid almost completely inhibited the growth of T.irregularis and no significant differences were found among samples at different medium pH values.