The Richtersveld is situated in the most arid region of South Africa and can be interpreted as the southerly part of the Namib Desert (Koch 1962). This semi-desert, with a precipitation well below 150 mm per year, is unexpectedly rich in plant and animal life correlated with a high diversity in terms of climate and geology. This unusual biodiversity, with a high rate of endemism, is the result of a large supply of different habitats, and is also a product of a long floristic history. The border of two fl oristic kingdoms, Greater Cape Flora and Palaeotropis is located within the Richtersveld (Jürgens 1991). It is expressed by a transition from a succulent dominated dwarf shrub-land on the western coast to a more open scrubland, with increasing grass cover, to the east.