The International Organization of Plant Biosystematists was founded in 1960 to promote international cooperation in the study of biosystematics. Traditionally, biosystematics applies methods beyond comparative morphology to analyze taxon boundaries and taxon relationships. Most research covers the range from population biology to the taxonomic levels of genus and family. Besides experimentation with the living plants to determine crossing relationships, character stability or plasticity, and the genetics of character differences, there is an emphasis on cytology for the investigation of ploidy and hybridization, the chemistry of secondary compounds and molecular marker systems from isoenzymes to comparative genomic sequencing. IOPB publishes a newsletter twice a year, and organizes an international symposium every three years.
Membership is open to all interested persons.