Several recent studies have reviewed the extent of fungal biodiversity, and have used these data as a basis for revised estimates of species numbers based on known numbers of plants and insects. None of these studies, however, have focused on fungal biodiversity in South Africa. Coinciding with the 100th anniversary of the National Collection of Fungi (PREM) in South Africa in 2005, it is thus timely to reflect on the taxonomic research that has been conducted in South Africa over the past Century. Information is presented on the extent of fungal collections preserved at PREM, and the associated research publications that have largely resulted from this resource. These data are placed in the context of the known plant and insect biodiversity and used as a basis to estimate the potential number of fungi that could be expected in South Africa. The conservative estimate is of approximately 200 000 species without taking into account those associated with substantial insect biodiversity.
