The Australian continent is dominated by land which can be described as desert or semi-desert. Between latitudes 20° S and 33° S only the narrow strip of the eastern highlands and the extreme south-west are adequately watered. The south and east of the continent receive appreciable rains in the winter, whereas the north and east receive their rains in the summer, the remainder receives no appreciable seasonal rainfall (see Fig. la). Although there is some dry sub-alpine land in south-eastern Australia, there is no portion of Australia which could be considered a cool or cold desert: the Australian deserts are all warm to hot. There have been few studies undertaken on the lichens of arid Australia. The first report to detail a significant number of Australian desert lichens was prepared by Müller Argoviensis (1893), who worked on lichens collected by Richard Helms, travelling with the Elder exploring expedition to central and western Australia. A few small collections were made and reported on in the following years, but not until 1971 did any further significant works on Australian desert lichens appear. Com mencing that year Rogers published on soil surface lichens in arid south eastern Australia (Rogers 1971, 1972a, 1972b, 1974; Rogers & Lange 1971, 1972). It is not only desert lichens which are poorly known in Australia: it was not until 1979 that the first modern handbook to the lichens of an Australian region was produced (Filson & Rogers 1979), and that is an incomplete account of the relatively depauperate (and largely desert) flora of South Australia. A discussion of some lichen distribution patterns in Australia, including desert species, can be found in Rogers & Stevens (1981).