About Kew's Herbarium
Herbaria are collections of preserved specimens that document the identity of plants. They represent reference collections with many functions including identification, research and education. At Kew, the Herbarium has a central role for research on plant biodiversity, with seven million specimens, including approximately 350,000 type specimens.
The collection at Kew is still growing with a yearly addition of around 30,000 new specimens through a programme of joint work with overseas colleagues, expeditions, gifts and exchanges with other institutes at home and abroad. The care of the collections, or curation, is undertaken with great precision.
When studied in the herbarium, specimens sometimes prove to be previously unknown species, which in due course will be described and named as new to science. Other specimens, once examined and determined, will provide essential research material for in-depth studies of systematics, micromorphology, biochemistry, and molecular genetics.
The Herbarium is also the repository of many voucher specimens. Such specimens are the only tangible record by which species used in experimental research can be compared.
What is a herbarium specimen?
Herbarium specimens are dried and pressed plants stuck on a sheet of cartridge or other archival quality paper with a label attached in the bottom right-hand corner to indicate provenance, collector, number and identity. Additional information, such as local uses, is often included in the label information. Kew's Herbarium collection comprises herbarium specimens cross-referenced with ancillary collections, such as the carpological collection, mostly for fruits and items too big to fit on a sheet of paper, and a spirit collection, used to store fragile items that would lose their three-dimensional shape once pressed, especially orchid flowers.
In the Herbarium, specimens are arranged systematically in the cupboards by family, region, genus and species, so that anyone can find an example of a particular species within minutes. It is, as it were, a card index box of the world's plants (in excess of 300,000 species) in a single building but with the sheets arranged systematically to reflect affinities and, usually, evolutionary relationships, rather than alphabetically.
More details on the preparation of herbarium specimens and their curation can be found in The Herbarium Handbook (Bridson & Forman, 1999).
The Herbarium contains over 350,000 type specimens - the original specimens on which new species descriptions have been based. These specimens, some dating back to the eighteenth century, typify and fix a species name for all time, and are invaluable to researchers into the taxonomy and systematics of plants. Together, they represent an irreplaceable international asset. Type specimens are vouchers for plant names and, as such, are the essential reference point for a name that botanists consult in seeking to apply names correctly.
Access to herbarium specimens
The Herbarium is the centre of an information network that brings together botanists from around the world. Every week, the Herbarium attracts an average of 50 visitors, about a quarter of which are overseas researchers. We also share our resources by sending out specimens on loan to overseas universities and specialist institutes.
As part of our ongoing digitisation programme, data for over 700,000 specimens and images for over 300,000 specimens have been made available online. These can be accessed through our Herbarium Catalogue.
Loan and visitor policies
The Herbarium is open to researchers by appointment only. A written request to visit is required at least two weeks prior to your proposed visit. Please send your request by email or letter to the address below. Your request must include the following information: full name and address of your institution, or home address if you are a private researcher, plant families you wish to study and proposed dates of the visit. If you are a student, your supervisor must make the visit request on your behalf. Please see our Loan Regulation Policy for more information.
Contact the Herbarium
Head of Collections
Herbarium, Library, Art & Archives
Royal Botanic Gardens, Kew
Surrey TW9 3AE
9am to 5.30pm Monday to Thursday
9am to 5pm Friday
Closed weekends and public holidays