Kew 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.
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.
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.
Many of these specimens were originally sent to Gay by Baron Jacques François Roger [fr], the governor of Senegal (1821–1826), who played an important role in furthering botanical research in the region.
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."
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.
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 (1839–1843), India and the Himalayas (1847–1851), and the western United States (1877).
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.
Each specimen includes a collector's label with provisional identification and contextual information, often accompanied by field notes, maps, and notebooks that provide valuable details about the time and place of collection.
New acquisitions follow a specific protocol: specimens are collected and dried between sheets of paper in presses, then undergo deep-freezing to eradicate pests before awaiting examination by specialist taxonomists.
After verification of plant identification, specimens are mounted on acid-free papers using appropriate adhesives that allow for future examination, then imaged, digitised, and finally incorporated into the collections.
Documentation has similarly evolved from handwritten labels to computer-generated ones including GPS data, though historical specimens preserve important contextual details from collectors like A.F.G.
The specimens offer information on plant morphology, distribution, environmental niches, phenology (flowering and fruiting times), and even genetic material that can be extracted for DNA studies.
The project was conceived to create a comprehensive index of all published names of seed-bearing plants, as Darwin had found Steudel's Nomenclator (the only existing work of this type) useful but outdated.
[17] The Index has been regularly updated through supplements since its initial publication, with the herbarium staff at Kew scanning the scientific literature to document new plant names and taxonomic changes.
Aberdeen used the Australian Lepiota specimens at Kew to revise this genus of mushroom-forming fungi in Australia, clarifying species boundaries and establishing new combinations.
According to David Mabberley, former keeper of the Herbarium, this has led to significant reorganization of collections, with an estimated 10–12% of plants being reassigned to different families based on genetic evidence rather than physical appearances.
[24] Despite modern technological advances like GPS devices and digital cameras, many fundamental research practices at the herbarium remain unchanged from Victorian times.
[9] The use of traditional methods alongside new technologies allows researchers to study current field guides and specimens from regions like Oman and Thailand in conjunction with historical collections from these areas.
[25] In agricultural applications, the collections support plant breeding programs by helping identify genetic traits controlling characteristics like height and colour.
[2] In 2022, Kew began an ambitious four-year digitisation project to create a complete digital catalogue of its herbarium and fungarium collections, which together comprise approximately 8.5 million specimens.
The process has revealed various conservation challenges within the collection, including detached plant parts and labels, deteriorated sheets, evidence of pest and mould damage, and wear from repeated handling over centuries.
[26] In 2023, Kew announced controversial plans to relocate the herbarium approximately 60 kilometres away to Thames Valley Science Park, owned by the University of Reading.
The proposed move, estimated to cost £200 million and take a decade to complete,[27] aims to address space constraints (the herbarium receives about 20,000 to 25,000 new specimens annually[4]) and concerns about fire and flood risks in the current historic building.
Over 15,000 people, including plant scientists worldwide and former Kew director Sir Ghillean Prance, signed a petition opposing the move.
Critics argue that separating the herbarium from Kew's gardens would disrupt crucial interactions between the collection and the living plants, and impede research collaboration.
They propose redeveloping the current herbarium building, which is not open to the public, as a science quarter to display historically important specimens, including those donated by Charles Darwin.
