Originating in Europe in the 16th century, botanic gardens are found in nearly every country in the world. Botanic gardens have had various roles during this time, including as physic gardens, as adaptation centers for commercial crops, as pleasure gardens, and more recently as conservation institutions. The role of botanic gardens in the conservation of Crop Wild Relatives is becoming increasingly important. At least 6000 taxa related to 68 crop genera are maintained by the world's botanic gardens with several gardens having specialist collections. The extent of infra-specific genetic diversity of these Plant Genetic Resources for Food and Agriculture (PGRFA) being conserved is currently unknown, although based on existing evidence it is likely to be low. However, these PGRFA collections, through display and education, play a significant role in linking the public to important issues, including food security and the need to conserve crop diversity. Today there are some 2700 botanic gardens in existence, and they are visited by over 500 million people every year. The majority of these gardens are found in temperate regions. At least 30% of all known plant species are found in botanic garden collections, including 41% of threatened species. These ex situ collections are conserved in a variety of ways, including as seed bank collections. Around 350 botanic gardens together maintain seed collections of 57,000 taxa. These seed bank collections have a variety of uses, including for research and reintroduction.