1979 B.Sc. Biochemistry, Eberhardt - Karls - University of Tübingen
1983 M.Sc. Biology (majors: Botany, Applied Botany, Microbiology), University of Hamburg, (Thesis: Studies in the characters in taxonomy of th genus Pleiospilos, Mesembryanthemaceae)American Association of Plant Taxonomists (ASPT)
Deutsche Botanische Gesellschaft
Deutscher Hochschulverband
Gesellschaft für biologische Systematik - boardmember
L'Association pour l'Etude Taxonomique de la Flore de l'Afrique Tropicale (AETFAT)
International Organization for Succulent Plant Study (IOS)´- boardmember
The Linnean Society of London