Cytogeographical studies of Hyacinthaceae in Africa south of the Sahara

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.