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Kew's Herbarium houses over seven million specimens and plays a central role in research into plant biodiversity on Earth.
Herbarium Wing E
Kew's Herbarium

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.

Search Kew's Herbarium Catalogue

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).

Photo collage of a selection of specimen sheets from Kew’s herbarium collections.
A selection of specimen sheets from Kew’s herbarium collections.

Type specimens

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.

The red cast-iron pillars and spiral staircases inside Kew's Herbarium
Inside Kew's Herbarium

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

Visits to the Herbarium

The Herbarium is open to researchers by appointment only.  If you would like to arrange a visit to the Herbarium, please ensure you apply by email at least two weeks in advance* of your expected arrival and your email must contain the following information:

Email Subject: Please start with the word VISIT and the date of arrival and departure (eg VISIT 20 – 23 July 2016). Please note we are closed at the weekend and public holidays.

Taxonomic groups: Please indicate all the plant families or genera you wish to look at.

Region of interest: Please indicate the continent and/or countries you are interested in.

Exact dates of stay: Please repeat this information, ensuring that there are at least two clear weeks from the email date to the date when you wish to visit Kew. 

Plant material: Please indicate if you intend to bring live or preserved specimens to Kew and what it is you are bringing in case permits are required, eg CITES. Please give yourself adequate time to inform Kew as permits may take time to issue.

Your details: Please ensure you include your full name and full address of your institution or your personal address if you are a private researcher.

Confirmation: If you are a student, please ask your supervisor to request the visit on your behalf to confirm that the research is required for your studies.

* For overseas visitors requiring a letter of support for a visa application, please ensure you apply for your visit at least three months in advance of your visit.

Visitors with potential commercial interests (eg a representative of a commercial horticulture company) should be asked to sign the non-commercialisation undertaking. Discuss with your line manager if you are unsure about how to proceed.

Please then email this information to and it will be picked up and forwarded to the relevant curator.

Loan requests

Please email requests for loans directly to where your request will be picked up. Please refer to our loan and sampling policy.

Read our loan regulation policy

Contact the Herbarium

Royal Botanic Gardens, Kew 
Surrey TW9 3AE 


Opening hours

9am to 5.30pm Monday to Thursday
9am to 5pm Friday
Closed weekends and public holidays