The collection is rich in diversity, with more than 370 families represented and including 1,600 types. The Kew Spirit Collection is probably the largest botanical spirit collection in the world, it is also one of the world’s largest and most diverse collections of orchids in spirit. The collection also houses the mycology spirit collection which contains more than 1,250 specimens with representatives from many genera.
Spirit preserved material is used where drying, pressing and mounting on a herbarium sheet is unsuitable, particularly where observation of the three-dimensional arrangement of flower parts or fruits are required.
Fluid preservation is the chemical stabilization of tissue to prevent autolysis. Fixation is used to prevent post mortem changes in the specimen, to stop cells breaking down after death. The fixative forms covalent bonds between molecules. Preservation refers to the maintenance of the specimen in a stable and usable condition by inhibiting enzymatic and microbial attack.
Kew’s Spirit Collection was started in 1930 by Victor Summerhayes, who was a curator of the Orchid Herbarium at the time. The existing specimens were incorporated into one collection; some date as far back as the 1830s and include a number of specimens collected in India in the 1850s by former Director of Kew, Sir Joseph Dalton Hooker.
The Spirit Collection is housed in a purpose-built, temperature-controlled store fitted with mobile banks of metal drawers to maximise storage. The larger jars (2,000 and 3,000ml) are stored on fixed metal shelving in enclosed cupboards to reduce the impact of UV light. Jar sizes range from 70ml to 3,000ml, with some out-sized jars for specimens such as the flowers and fruits of Aristolochia grandiflora and Musa lolodensis. The collection is maintained at between 12–15°C and 50% humidity: this temperature reduces evaporation and lowers the likelihood of fire. Adjacent to the store is a laboratory, where spirit specimen preparation work (including topping up and preparing new accessions from the Living Collection) are carried out.
The collection is arranged in specimen number order, according to jar size. This non-systematic arrangement removes the need to continually re-arrange the collection according to revisions and maximises storage.
The Spirit Collection is not isolated from the other Kew collections. Many specimens have associated herbarium sheets, carpological material and DNA voucher specimens in the Herbarium and Jodrell Laboratory. The collection continues to grow with material incorporated from overseas fieldwork and from Kew’s Living Collection. The collection is used mainly for taxonomic research by staff and specialists from around the world. But it is also a valuable source of material for non-taxonomic research, and as such is used by a wide range of scientists, artists and students.
Many specimens have been used for botanical illustration, as spirit material retains a life-like appearance and have appeared in Curtis's Botanical Magazine.
The Herbarium Catalogue (HerbCat) holds records of all specimens in the collection and can be searched by many categories including plant name, plant collector and country.
The Spirit Collection is open to academic visitors upon request and to the public via special events such as open days. Spirit material can also occasionally be viewed on display in the Herbarium reception or the Library Reading Room exhibitions.
Contact via the Herbarium
Royal Botanic Gardens, Kew
Surrey TW9 3AE
Kew’s Herbarium contains around seven million preserved vascular plant specimens. These specimens contain a wealth of information about plants that have been collected around the world over the past 170 years.