Kew Herbarium
The Kew Herbarium is one of the world's largest and most historically significant herbaria, housed at the Royal Botanic Gardens, Kew in London, England. Established in the 1850s on the ground floor of Hunter House, it has grown to maintain approximately seven million preserved plant specimens, including 330,000 type specimens. The herbarium's collections, which include specimens dating back to 1700, represent about 95% of known vascular plant genera and 60% of described fungi, with specimens collected over 260 years of botanical exploration. The herbarium processes around 5,000 specimen loans annually and hosts approximately 3,000 visitor-days of research visits each year, supporting a wide range of botanical research.
The herbarium's development has been closely tied to British botanical exploration and colonial expansion, with contributions from influential directors like Sir Joseph Dalton Hooker and major acquisitions including the Gay Herbarium. Research at the herbarium has contributed to botanical taxonomy, with publications such as the Index Kewensis, initiated with funding from Charles Darwin in 1882, and the Kew Record. The facility has undergone several major expansions since its first purpose-built wing was constructed in 1877, with Victorian architecture that includes spiral staircases, iron columns, and vast handcrafted wooden cupboards. In 2022, the herbarium initiated a £29 million digitisation project to produce high-resolution images of its collection, with a target completion date of 2026.
The herbarium is a resource for botanical research in taxonomy, conservation, ecology, and climate science. Its specimens offer data that aid in tracking environmental changes, studying plant diseases, and identifying new species, as demonstrated by the 2022 discovery of Victoria boliviana, the world's largest water lily species, which had remained unrecognised in the collection for almost two centuries. The herbarium's future is currently subject to debate, with controversial plans announced in 2023 to relocate the collection to Thames Valley Science Park, prompting discussion about the balance between preservation needs, research accessibility, and maintaining the historic connection between the herbarium and Kew's living collections.
History and development
Prior to the establishment of Kew's herbarium, botanical specimens in London were primarily studied at Sir Joseph Banks' collection in Soho Square. This changed after William Jackson Hooker became Kew's Director in 1841, when he began allowing researchers to access his substantial private collection at his residence near the gardens. The herbarium officially began in 1852 when the ground floor of Hunter House, an early 18th-century Queen Anne style building on Kew Green, was allocated to store both Hooker's collection and the herbarium and library of William Arnold Bromfield. Hunter House had previously been the residence of the Duke of Cumberland until his death in 1851, and formed part of a larger complex with the adjacent Meyer's House. In 1876, parts of Hunter House, including its drawing room, south room, kitchen and river frontage steps, were demolished to make way for the herbarium's first purpose-built wing. The following year saw the appointment of the first curator, Allan Black.The herbarium's collection includes specimens from many notable historical figures, illustrating its connection to exploration and scientific discovery. Among its treasures is a specimen of Faroa nyasica collected by David Livingstone in the 1860s during his explorations of what is now Malawi. While the collection includes a 4,000-year-old olive tree branch from Tutankhamun's tomb, its oldest officially catalogued specimen is Indigofera astragalina, collected by Daniel du Bois at Fort St. George in India in 1700. Other early specimens are those collected by Samuel Browne, a surgeon working for the East India Company in the 1690s. Browne collected plants around Madras and collaborated with Tamil and Telugu speakers to record local plant names and uses.
The early herbarium grew rapidly through both government grants and private donations. In 1853, the herbarium received William Bromfield's Flora Vectensis. An expansion took place in 1854 when George Bentham donated his herbarium and library to the nation, on condition they would be housed at Kew and remain accessible to botanists. After William Hooker's death in 1865, the government purchased his herbarium and library in 1866.
Many significant historical collections were incorporated during this early period, including Allan Cunningham's Australasian specimens, William John Burchell's collections from Saint Helena and South Africa, Robert Brown's British specimens, Hewett Watson's British collections, Amelia Griffiths's algae, William Wright and Johan Peter Rottler's Indian specimens, and several general herbaria. The extensive Indian collections of Hooker and Thomas Thomson that reached Kew in 1851 contained an estimated 8,000 species. Another valuable acquisition was the herbarium of Jacques Gay, which arrived at Kew in 1868. This collection included early specimens from Senegal collected in the 1820s by Claude Richard, the founder of the Richard Tol botanical gardens, and by Döllinger. Many of these specimens were originally sent to Gay by Baron, the governor of Senegal, who played an important role in furthering botanical research in the region.
The first purpose-built wing of the herbarium was constructed in 1877, prompted by the need for additional space to accommodate botanical specimens collected during exploration of the British Empire. Around 1878, a large hall was added – a quadrangular structure eighty-six feet by forty-three feet, with a ground floor and two galleries connected by two spiral staircases and lit by forty-eight windows. A second hall of the same dimensions was completed around 1903. The facility underwent several further expansions between 1902 and 1969, including basement extensions. The facility has expanded periodically to house its growing collections, with extensions added approximately every 40 years. This pattern of growth continued with a modern wing added in 2009.
In 1969, a major reorganisation of British botanical collections took place when Kew transferred its bryophytes, algae, and most of its lichens to the British Museum on permanent loan, receiving in exchange the British Museum's fungal collections. By this time, the herbarium's holdings had grown substantially – from over 2,000,000 specimens mounted on 1,500,000 sheets in 1903 to its current size of approximately seven million specimens.
Architecture and design
The original 1877 Wing C exemplifies the grand Victorian architecture that characterises much of the herbarium. Its interior features a soaring rectangular warehouse design with three-story spiral staircases beside tall red iron columns, in what staff affectionately call a "jailhouse style." The space is flooded with natural light from enormous windows - a deliberate 19th-century design choice to minimize the use of gas lanterns around the paper specimens. Vast handcrafted wooden cupboards are arranged in rows, creating what staff call small "cells" between the stacks that point toward the centre of the room. The historic wing has a unique atmosphere, marked by the scent of old paper and preserved specimens.Subsequent wings retained similar architectural features to the original design through the early 20th century, with Wing B matching the galleried interior and woodwork of Wing C. The newer wings show the evolution of herbarium design – Wing E replaced the traditional wooden cupboards with wheel-operated compactor shelves and substituted windows for modern climate control systems maintaining a constant 18°C. The facility includes two cavernous basements housing specialised collections. These storage areas feature custom-made boxes designed for preserving particular specimen types, with shelving extending deep into climate-controlled storage areas.
Notable directors and staff
Joseph Dalton Hooker
Sir Joseph Dalton Hooker served as Assistant Director and then Director of Kew Gardens. During his tenure, he substantially expanded the herbarium's collections through his own extensive botanical expeditions and by establishing a wide network of scientific exchanges. Hooker conducted several major collecting expeditions, including voyages to Antarctica and the South Pacific, India and the Himalayas, and the western United States. His Indian expedition alone yielded over 150,000 specimens representing around 7,000 species. During his travels in Sikkim, he collected specimens of 25 previously unknown species of rhododendron. His botanical artwork and field sketches from these expeditions are preserved in Kew's art collection.A prolific author, Hooker formally described over 12,000 new plant species during his career. His major publications included the multi-volume Flora of British India and Genera Plantarum, the latter written with George Bentham establishing a systematic structure for plant classification that remained in use at Kew for over 130 years.
Peter Shaw Green
served as Keeper of the Herbarium and Deputy Director of Kew Gardens from 1975 to 1982. He was particularly known for his expertise in the taxonomy of Oleaceae and the flora of the south-western Pacific. During his tenure, he reorganised the herbarium's sectional structure to be based on systematic rather than geographical responsibilities. Green also played a crucial role in establishing the management of the Herbarium and Library as a single unit, which later evolved into the Herbarium, Library, Art & Archives department.Green joined Kew in 1966 in the Australian Section of the Herbarium, later becoming Deputy Keeper and editor of the Kew Bulletin. In this role, he cleared the mounting backlog of manuscripts and restored the publication to a regular schedule. After retirement in 1982, he continued his research as an Honorary Research Fellow, contributing accounts of the Oleaceae to various floras including the Flora of China and Flora of Thailand.