The campylidia hypothesis, first introduced by Müller Argoviensis (1881) and recently restored by Vězda (1983), for the erect helmet-shaped structures found on foliicolous lichens and usually known as ‘ Pyrenotrichum ’ is adopted as being the most satisfactory. In the Badimia pollilensis aggregate, campylidia are shown to derive from primordia identical to those of the apothecia. In the genus Sporopodium, algal cells are included in the conidiogenous layer and are dispersed together with conidia. This also seems to be the case in the genus Loflammia. Short descriptions are given for the most common campylidium known as ‘ Pyrenotrichum splitgerben ’ and for another not yet assignable to a peculiar genus. Loflammia denwulinii sp. nov. is described from New Guinea.

Observations have been made on the effects of different storage treatments, either 100°0 or 0°0 r.h., 12 h light:12h dark or 24 h dark for 2 days, on the ultrastructure of the phycobionts of Lobaria amplissima and Lasallia pustulata. After storage, Myrmecia, in the more desiccation-sensitive lichen L. amplissima, showed an increased number of cytoplasmic storage bodies which had more frequently dark contents and a half-moon-like appearance.Trebouxia, from the desiccation-resistant L. pustulata, showed major cellular disorganization when stored at 100°0 r.h. in the light:dark regime, whereas, in the dark, reorganization of thylakoids into a parallel arrangement occurred. Treatment at 0°0 r.h. in the light:dark regime induced an accumulation of starch around the pyrenoid of Trebouxia and, in the light:dark and dark regimes, a peripheral location of pyrenoglobuli without a decrease in the total volume of lipid material. The results are discussed in terms of the utilization and mobilization of reserve substances and the habitat preferences of the two lichens.

Axenic, spore to spore resynthesis of Xanthoria parietina has been accomplished on an agar substrate.

The new genus Edwardiella Henssen with the single species E. mirabilis Henssen is described in the Lichinaceae to include a holocarpous lichen. Colonies of the Gloeocapsa-phycobiont which are invaded by the fungal hyphae develop directly into apothecia or pycnidia. The apothecia are thallinocarps. The lichen was collected in the subantarctic Marion Island where it was mainly growing in lichenized tufts of Scytonema. Two new combinations, Gonohymenia nigritella (Lettau) Henssen and G. hondoana (Zahlbr.) Henssen are made.

Solorina simensis Hochst. ex Flotow differs from S. saccata (L.) Ach. in spore ornamentation and chemical properties as well as in its mainly plane apothecia and blue-green photobiont. It is here considered a distinct species. Solorina crocoides (Nyl.) Hue is briefly commented upon.

A new species of Collema is described which, like C. callibotrys, has numerous minute globose apothecia in clusters but, unlike that species, has unornamented spores. It is recorded from Tanzania and Uganda.

Mature as well as juvenile stages of thalli and apothecia occurring on numerous meteorite fragments found on Ella Island can be referred to 10 genera of lichens: Acarospora, Candelariella, Gyalidea, Lecanora, Lecidea, Physcia, Pseudephebe, Polysporina, Rinodina and Xanlhoria. In their colonization phase these lichens are influenced by the mineralogy and chemistry of the meteorite fragments. Thus Xanlhoria shows a distinct preference for the meteorite minerals rich in iron, whereas Candelariella appears to avoid these minerals.

The lichen floras occurring on high-level quartzite, Moine granulite, syenite and calcareous schist in the northern Highlands of Scotland are compared. Rock mineralogy is of overriding importance in determining the assemblages present, though this factor can be modified by extraneous nutrients. Local climatic conditions favour a cloud zone community dominated by ‘alectorioid’ species, produce stony ablation surfaces at a low level and allow maritime species to grow far inland. Ben Hope, with 34 ‘ rare ’ species recorded, is confirmed as a major site for alpine calcicolous lichens. Lecanora chlorophaeodes Nyl., a species new to Britain, is reported from the summit of Ben Loyal. In contrast, the extremely hard, acid, nutrient-deficient quartzite of Foinaven displayed a flora characterized by a very low species diversity.