Economic Botany Collection at Kew

By Susanne Masters (on Twitter as  @ethnobotanica and Instagram as @mastersmiss).

At head height in the aisle by Myrtaceae there is a faint but recognisable smell of clove (Syzygium aromaticum) in the Economic Botany Collection (EBC) at Kew. A reminder that this archival collection is more animate than written words or captured images. Despite the passage of time its samples of useful plants and plant products retain their chemistry and DNA.  Any ethnobotanist passing through Kew enjoys a guided rummage in the EBC.

Spurred on from connections made at the recent SEB Meeting in Jamaica, a student meet-up was organised at Kew Gardens. On 17^th August 2022 we met to discuss restarting UK SEB chapter meetings and took the opportunity to visit the collections. On this visit to the EBC most attendees had already been at least once, yet Dr Mark Nesbitt could provide novel sights for all from this collection, which contains about 100,000 accessions from around the world.  It is currently the largest biocultural collection in the world.

Mark opened a box containing an iridescent jacket, accession number 91934 . Dyed indigo using Assam indigo (Strobilanthes cusia) from Acanthaceae, it had been beaten to its metallic sheen with wood.   On the basis of visual inspection the group thought the underlying fabric might be hemp. A practical session on identifying fabrics with burn tests could be on the agenda outdoors at the next meet up led by Anushka Tay, who is a PhD researcher with University of the Arts London researching material objects and their impact on cultural identity.

Accessions in the EBC aren’t just objects, they are storytellers of their use, how they came to join the collection, and teachers of past knowledge for future purposes. Looking at a lacebark bonnet made from the phloem of lacebark tree (Lagetta lagetto), from Thymeleaceaefamily, EBC accession number 44939 , prompted discussion of the mystery of trees that allow their inner bark to be easily separated, whether lacebark might be sustainably cultivated, and how older institutes can support the development and revival of collections in places where objects originate.

In most trees the phloem, which can be thought of as botanical veins, run parallel. In lacebark trees they divide and re-join forming a fine mesh that resembles lace.  Study of other members of Thymelaeaceae whose bark is used might provide direction on how to harvest lacebark sustainably.  Environmental history recording deforestation of Jamaica suggests that the tree’s current rarity in Jamaica may also be due to habitat loss as well as collection for use and trade. Recently samples of lacebark offered to Kew was redirected, with consent from the donor, to Jamaica where they have joined a biocultural collection.  

There are thousands of samples of cinchona, from Cinchona species, Rubiaceaefamily, in Kew’s collection. Not because of immense contemporary interest in its use as a bittering agent for tonic water but due to medicinal use of cinchona to treat malaria.  Many of the samples now at Kew came from pharmacy schools, where they were important references to be consulted when verifying samples of bark sold as cinchona. One of the tricks used to pass off cherry bark as cinchona was to stain it dark with molasses. Manipulating colour was a superficial but effective disguise, which could be sabotaged by comparison to genuine cinchona and seeing the difference in physical structure between cinchona and cherry bark. Kim Walker, whose PhD research on the quest for quinine at Royal Holloway and Kew showed us some of her favourite samples in the EBC.  For those curious about the cinchona, quinine and tonic water Kim and Mark’s book on the natural history of tonic water Just the Tonic provides a detailed account.

Kew’s example of a The Wardian Case, a miniature travelling greenhouse, is not just an illustration of how living plants were redistributed across the world. It is also an artefact of politics and societies practising extractive trade in plants. Mark recommended Luke Keogh’s book  ‘The Wardian Case: how a simple box moved plants and changed the world’ for covering not just its history of expanding ranges of crops but also darker aspects of plant commerce including introduction of invasive species and imperialism.

Repurposing economic botany collections for modern times depends on transparent documentation of their history and acknowledgement of an extractive past. These collections have found new utility in connecting nature and human culture, not least in inspiring a reassessment of the role of biodegradable materials from botanical sources that lost favour in a relatively brief but damaging time of using petrochemicals to manufacture disposable materials impervious to decay.  It’s important to curate and even rescue ethnobotanical collections. A much-consulted assemblage of gums and resins now kept in the EBC at Kew was saved from deposit in a skip – the sad fate of too many collections. 

Biocultural collections are a growing network. Kenneth Walker, who is studying Afro-Caribbean ethnobotany, commented that he had seen a Poaceae sample collected by Mark at New York Botanical Garden. While the August meet-up at Kew was a learning opportunity, it was also a social space and equally valuable to connect in person with people whose work we encounter in different places. Plans are in progress for another UK meeting in Spring 2023.    

Photo credits

Royal Botanic Garden, Kew

Harriet Gendall