A survey of the carbon isotope composition (13C/12C) of plants in the Central Namib Desert has been undertaken to ascertain the significance of the C-4 photosynthetic pathway to the desert flora. Using this criterion it is found that all the grasses and some sedges are of the C-4 type, while the majority of the other species are C-3. Of the latter group Trianthema, Salsola, Gisekia and Blepheris show the high 13C-content characteristic of "Kranz" or strong CAM plants. The C-4 pathway is thus an efficient, but by no means an obligatory adaptive condition for survival in a hot desert environment. Keywords: Isotope ratio measurements, Acid metabolism (CAM), Angiosperms, Aridity, Aspartic acid, ChIoropIasts, Drought tolerant, Episodic showers, Inselberge, Mesaphyll cells, Natural habitat, Photosynthesize and Xerophytic niche.