The geographical distribution of different karyotypes in Tropical African genera of Hyacinthaceae is studied. In Albuca, Dipcadi, Drimia (including Urginea), and Drimiopsis there seem to be a general trend of increasing level of ploidy and/or basic number. There is also a tendency of increasing karyotype asymmetry from the south towards north and west. Southern Africa is therefore probably a centre of dispersal (and origin?) for these genera. In the subgenus Urophyllon of Ornithogalum the cytological conditions are in accordance with a hypothesis of northern origin and migration via East Africa towards south and west. Several new chromosome numbers are presented.