Participating institutions commit to holding and developing a collection(s) of documented living plants according to professional standards of collections management. They assemble a comprehensive representation of a designated plant group such as a family or genus, or alternatively as a floristic region or other theme. The primary focus can be on taxonomic diversity including cultivars, or genetic diversity for conservation-based collections representing different populations throughout their natural ranges. This commitment involves replication of taxa within an institution and complementary replication of taxa among different institutions to ensure germplasm preservation. Multiple institutions might contribute to the distributed holdings large plant groups where no single institution is capable of forming a comprehensive collection due to climatic and physical space limitations.