The Index Herbariorum provides a global directory of herbaria and their associated staff. This searchable online index allows scientists rapid access to data related to 3,400 locations where a total of 350 million botanical specimens are permanently housed (singular, herbarium; plural, herbaria). The Index Herbariorum has its own staff and website. Overtime, six editions of the Index were published from 1952 to 1974. The Index became available on-line in 1997.
The index was originally published by the International Association for Plant Taxonomy, which sponsored the first six editions (1952–1974); subsequently the New York Botanical Garden took over the responsibility for the index. The Index provides the supporting institution's name (often a university, botanical garden, or not-for-profit organization) its city and state, each herbarium's acronym, along with contact information for staff members along with their research specialties and the important holdings of each herbarium's collection.