For the past three centuries, scientists have documented the earth’s plant and fungal diversity through dried reference specimens maintained in collections known as herbaria. As of December 1 2018, there are 3,095 active herbaria in the world today, with approximately 12,278 associated curators and biodiversity specialists. Collectively the world’s herbaria contain an estimated 387,513,053 specimens that document the earth’s vegetation for the past 400 years. Index Herbariorum is a guide to this crucial resource for biodiversity science and conservation.

The Index Herbariorum (IH) entry for an herbarium includes its physical location, URL, contents (e.g., number and type of specimens), founding date, as well as names, contact information and areas of expertise of associated staff. Only those collections that are permanent scientific repositories are included in IH. New registrants must demonstrate that their collection is accessible to scientists, and is actively managed. Each institution is assigned a permanent unique identifier in the form of a one to eight letter code, a practice that dates from the founding of IH in 1935.

The first six editions of Index Herbariorum were published by the International Association for Plant Taxonomy in the Netherlands (1952–1974). Dr. Patricia Holmgren, then Director of the New York Botanical Garden, served as co-editor of edition 6, and subsequently became the senior editor of IH. She oversaw the compilation of hard copy volumes 7 and 8, and Dr. Noel Holmgren, a scientist on the NYBG staff, oversaw the development of the IH database, which became available on-line in 1997. In September 2008, Dr. Barbara M. Thiers, Director of the NYBG Herbarium, became the editor of IH.

A grant from the U.S. National Science Foundation (DBI grant # 1600051) has funded changes to Index Herbariorum. With this funding, the biodiversity information management team at The New York Botanical Garden has modified the structure of the database to include more information about the contents of herbaria (e.g., numbers of total specimens for the major groups of organisms stored in herbaria), the status of collections digitization, and the data portals through which the data can be accessed. We have created an API to facilitate the inclusion of Index Herbariorum data in other applications.

Additionally, we have changed the update procedure for Index Herbariorum. Herbaria can now update their own information and new herbaria can self-register. All updates and new registrations will be provisional until reviewed and accepted by the Editor, and will not appear online until accepted.

How to Cite Index Herbariorum:
Thiers, B. M. (updated continuously).  Index Herbariorum.  https://sweetgum.nybg.org/science/ih/