The lichen biota of the Namib Desert has been studied in detail only during the last two decades. Two decades earlier, a paper by Mattick (1970) dealt with the lichen biota in the fog desert and with the luxurious growth of the 'lichen fields'. The comparative paucity of attention accorded these remarkable habitats in early years is surprising given the long-standing interest on the part of biologists for desert organisms and their diversity and physiology. Fog deserts offer lichens particularly favourable conditions despite the extremely low levels of precipitation. One of the main reasons for the poor knowledge of the lichenized fungi and their ecology has been the lack of adequate information about the taxonomy of the species. In some cases, even frequent species have not been identifiable until recently. Key words: Biodiversity, lichenized fungi, Rinodina, Namib Desert, Namibia.