Fourteen species of Pseudocyphellaria having tomentose or pubescent lobe margins and scabrid-areolate, or ±tomentose upper surfaces occur in southern South America (including Juan Fernandez, the Falkland Islands and South Georgia) south of latitude 34°S. A key and details of the anatomy, chemistry, distribution, morphology and nomenclature of each species are given. Two main groupings are represented in this study: (1) taxa with a ±scabrid-areolate or pubescent upper surface, having sessile, laminal apothecia with a well-developed excipulum proprium (lacking photobiont cells) and containing colourless, acicularfusiform spores (P. compar, P. endochrysa, P. scabrosa and P. vaccind); (2) taxa with a ±tomentose upper surface, having mainly marginal, pedicellate apothecia, with a prominent excipulum thallinum (containing photobiont cells) and with yellowbrown to brown, ellipsoid spores (P. dubia, P. guillemini, P. hirsuta, P. mallota, P. obvoluta, P. pilosella, P. santessonii and P. subrubelld). Pseudocyphellaria piloselloides and P. pluvialis are not known fertile. Pseudocyphellaria pluvialis R. Sant., P. santessonii D. Galloway and P. scabrosa R. Sant., are newly described and a new combination, P. guillemini (Mont.) D. Galloway, is proposed.

The nomenclature, chemistry, taxonomy, distribution and ecology of Aspicilia tuberculosa (Ach.) Laundon comb, nov., Buellia ocellata (Flotow) Körber, Pycnothelia papillaria Dufour, Rhizocarpon richardii (Lamy ex Nyl.) Zahlbr. and Rinodina aspersa (Borrer) Laundon comb. nov. are discussed. Aspicilia tuberculosa, related to A. caesiocinerea, has apparently not been collected since c. 1830 and may now be extinct. The name Buellia verruculosa has been wrongly applied and the species should be called B. ocellata. The name Pycnothelia papillaria is retained, but with a modified author citation. Rhizocarpon constrictum is a synonym of R. richardii. Rinodina fatiscens is shown to be a synonym of R. aspersa. The nomenclature of Aspicilia caesiocinerea and Rinodina atrocinerea is also considered, the latter requiring change of author citation.

Aspicilia excavata Thor & Timdal sp. nov. is described and reported from Austria, Finland, Norway and Sweden. It is usually sterile and mainly characterized by an indeterminate thallus composed of small, white pruinose squamules excavated from the margin by dark brown to black soralia. The species grows on calcareous rocks and mortar, mainly on steep to overhanging faces.

Three new maritime saxicolous Ramalina species are described from Australia, R. litorea, R. whinrayii and R. caespitella N. Stevens spp. nov. The first species is tropical in occurrence, whereas the last two are temperate taxa and endemic to Australia.