Plant diversity in the British Virgin Islands, linking the past with the present

A century after Kew’s first study of the British Virgin Islands’ plants, modern research is guiding new ways to protect its incredible botanical heritage

Two scientists look at plants on a rocky outcrop next to the see

In the early 1900s, Walter Charles Fishlock, a Kew gardener, embarked on a remarkable journey across the Atlantic to the British Virgin Islands (BVI), in the Caribbean.

The dried plant specimens he collected during his time there became one of the earliest records of the islands’ astonishing plant diversity.

Fishlock’s work at the Agricultural Experimental Station on the island of Tortola – now the site of the JR O’Neal Botanic Garden – laid the foundation for botanical studies in the region. Today, The National Parks Trust of the Virgin Islands (NPTVI) manages the site, continuing the conservation legacy that Fishlock helped to begin.

Over the past 25 years, Kew and NPTVI have worked together to deepen our understanding of the islands’ biodiversity – a partnership that bridges the gap between a century-old legacy and cutting-edge modern science.

This work will help us save the BVI’s unique plants that are essential for ensuring healthy ecosystems for the local people and nature, building resilience which is crucial in the face of potential environment changes caused by climate change.

A herbarium specimen of Vachellia anegadensis — *Vachellia anegadensis*, an endemic plant species to the BVI. Collected in 1914 by Walter Fishlock on the island of Anegada. This species is Endangered in the wild © RBG Kew

A herbarium specimen of Ilex urbania Loes — *Ilex urbaniana* is a restricted plant species, endemic to the Puerto Rican Bank. This species is Vulnerable in the wild. © RBG Kew

How do you protect the plants of an entire archipelago?

Conserving biodiversity starts with understanding it in detail. For our Darwin Plus-funded project (DPLUS183), this means constructing a comprehensive “tree of life” for the entirety of BVI’s flowering plant life (approximately 785 species!) and assessing the likelihood of its extinction.

By mapping the islands’ species diversity and combining this with data on species richness and extinction risk, we aim to create a robust conservation plan for BVI’s plant life.

Three people hold a long sheet of paper that shows a tree of life — The work has involved constructing a comprehensive tree of life for the entirety of BVI’s flowering plant life © RBG Kew

Journeying into the field

To complete our dataset for the remaining species, we journeyed out to BVI in three expeditions, December 2023 and March and November 2024.

Fieldwork in BVI is no small feat. The islands’ rugged terrain and dense vegetation often defy the picture-perfect vision of a Caribbean paradise. Many of the species we targeted for collection were found in remote areas, requiring careful navigation and expert botanical knowledge for identification.

A group of researchers sort plants on a forest floor — Studying and collecting samples at the Sage Mountain National Park, on the island of Tortola. © RBG Kew/National Parks Trust of the Virgin Islands

A woman takes notes next to a large plant — Colleague from the National Parks Trust of the Virgin Islands collecting native grass at Great Tobago National Park © RBG Kew/National Parks Trust of the Virgin Islands

Historic practices, modern uses

The preparation of herbarium specimens has remained largely unchanged since Fishlock’s time, continuing to play a vital role in botanical research. A well-prepared herbarium specimen must clearly display key identifying features of the plant, making careful selection and preparation essential. For instance, fruits and flowers, which are often crucial for species identification, are prioritised when selecting and pressing specimens.

In the field, pressing plant specimens is a race against time. Quick drying is critical to prevent the growth of fungal moulds, which can render specimens unusable. This is particularly challenging due to the humid Caribbean environment.

We pressed our specimens between layers of newspapers and stacked them in portable wooden presses, but drying the plants thoroughly often required improvisation. We found an innovative solution: leaving the specimen presses inside hot cars under the sun. The heat accelerated the drying process, allowing most specimens to dry completely within a few days depending on the species.

Once dried, we transported the specimens to Kew for further preparation.

Person holds a box of tea bags while in a forest — Storing the leaf samples in tea bags with silica gel helps the drying process © RBG Kew/National Parks Trust of the Virgin Islands

Two people talking while within a forest in the British Virgin Islands — Capacity building is one of the key parts of the project © RBG Kew/National Parks Trust of the Virgin Islands

Success through collaboration

Between November 2023 and November 2024, our team collected 653 herbarium specimens and associated DNA samples from the field. These collections represent 90% of our BVI target list, though further identification work at Kew is still required to confirm our results.

We collected each herbarium collection in sets of three, ensuring that each plant’s duplicates can be preserved and shared across multiple institutions. One specimen will join the Kew herbarium collections, housed alongside the specimens collected by Fishlock over a century ago. Another duplicate will contribute to the collections of the BVI National Herbarium, while the third will enrich the MAPR Herbarium at the University of Puerto Rico, Mayagüez Campus.

Three women sit at a bench studying plant specimens — Training BVI colleagues to press herbarium specimens. Capacity building is one of the key outputs of this Darwin Plus project (DPLUS183). © RBG Kew/National Parks Trust of the Virgin Islands

This collaborative sharing of specimens ensures regional accessibility and support broader conservation efforts.

The success of this ambitious project was made possible through the invaluable partnerships and expertise of numerous collaborators. Our work was strengthened by the NPTVI, which has been Kew’s long-term partner in conservation efforts on the islands. We were also fortunate to work closely with experts like Jeanine Vélez-Gavilán from MAPR and Omar Monsegur from the US Fish and Wildlife Services (USFWS) – Caribbean Ecological Service Field Office (Puerto Rico).

Additionally, Clare Weaver and Dewey Hollister from the Virgin Island Rare Plants Initiative (VIRPI), based in the US Virgin Islands and Octavio Rivera Hernández from Puerto Rico have joined the field expeditions. Their involvement not only ensured the success of the project but also helped build stronger regional collaborations for plant conservation.

Group of people stand outside for a photo — Back row, left to right: Dewey Hollister, Creightanya Brewley, Colin Clubbe, Jahkoy Gordon, Clare Weaver, Deborah Seddon, Nancy Pascoe, Omar Monsegur, Juan Viruel. Front row, left to right: Sara Barrios, Dequan Leonard, Simeon Cabral © RBG Kew

As of now, the DNA samples collected during field expeditions are undergoing analysis at Kew’s Jodrell Molecular Lab. Simultaneously, the herbarium specimens are being identified and carefully mounted onto sheets of archive-quality paper for long-term storage and further studies. Each specimen is meticulously labelled with detailed information about its collection, ensuring that future researchers and conservationists can build on this work.

Who can say what the future holds? Perhaps, a century from now, researchers will turn to the collections we’ve created, uncovering insights and pursuing studies we can’t yet imagine, just as we’ve done with Fishlock’s work from over 100 years ago.

The success of this project is a testament to the power of collaboration, spanning institutions, countries, and even centuries. Together, we are working to ensure that the rich and unique plant diversity of the British Virgin Islands is not only documented but also protected for generations to come.