16 October 2025

9 min read

Behind the Red List: How Kew protects the world’s most threatened plants

In the October 2025 Red List update, Kew contributed more than 700 Red List assessments. Here’s how partnerships, fieldwork and taxonomic expertise made it possible.

By Jack Plummer , Hannah Wheatcroft and Hannah Bevan

[画像:IUCN Congress 2025 blog banner ]

To protect life on Earth, we need to know which species are most at risk of disappearing. Without that knowledge, conservation would mostly be guesswork. We wouldn’t know where to act first, how to spend limited resources, or whether we’re making progress in slowing biodiversity loss.

That’s where Red Listing comes in. Red Listing is the process of assessing a species’ risk of extinction, using a clear set of scientific rules. It asks questions like: Where are they found? Are their populations shrinking or stable? How many individuals are left? The answers decide how a species is classed, for example: Least Concern, Endangered, Critically Endangered or even Extinct.

Wrightia sirikitiae is a small tree only known from Thailand

Named after Queen Sirikit of Thailand, Wrightia sirikitiae is a small tree only known from Thailand. It is assessed as Endangered and is threatened by limestone mining, maintenance around tourist sites (caves), and collection. © Naiyana Tetsana / RBG Kew

The results are published in the IUCN Red List of Threatened SpeciesTM, the world’s most trusted source of information on extinction risk. From elephants and corals to wildflowers and fungi, it now includes assessments for over 170,000 species - guiding conservation action across the globe.

Kew is a Red List Partner, with a focus on plants and fungi, many of which are still poorly studied. In the latest update, launched during the 2025 World Conservation Congress in Abu Dhabi (that myself Jack Plummer and Hannah Wheatcroft attended), more than 700 assessments involving Kew scientists were published – one of our largest contributions to a single update.

A person standing next to a large digital screen displaying plant conservation information in a bright conference venue.

Jack Plummer next to a poster on Ethiopia’s endemic flora at the IUCN World Conservation Congress 2025 in Abu Dhabi. © RBG Kew

A person standing beside a large digital poster display in a modern conference hall, showing research slides about plant conservation.

Hannah Wheatcroft next to a poster on rattans of southeast Asia at the same IUCN World Conservation Congress © RBG Kew

At the World Conservation Congress, Hannah and I presented digital e-posters (see links) on projects assessing Ethiopia’s endemic flora, and rattans of southeast Asia. Yet, these significant projects only capture a relatively modest snapshot of Kew’s overall Red Listing output.

Here, we highlight some of the other projects, species and collaborations behind those assessments - and how Red Listing helps turn scientific data into real conservation action.

Addressing gaps on the Red List for CITES-listed species

One way species come under pressure is through international trade – for timber, medicine, food, ornamentals and more. To ensure this trade is sustainable and legal 184 countries have signed up to the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).

Dried ginseng preserved in a specimen jar

Dried ginseng preserved in a specimen jar, ready for research © RBG Kew

Dried ginseng preserved in a specimen jar

By listing species in its three Appendices, countries signed up to CITES have agreed how species can be traded across borders, with the aim of ensuring that use is sustainable and does not drive species towards extinction.

For plants listed on CITES, Red List assessments can be important indicators of effectiveness of regulation of international trade. Most plants covered by CITES are part of family-level listings e.g. all orchids or all cacti – but in cases where international trade is highly targeted, individual species may be listed on the Appendices.

Surprisingly, some species known to be directly impacted by international trade are not yet represented on the Red List.

Following the completion of a Defra-funded project collaboration between our assessment team and Science Policy team, over 90% of plants listed at species, subspecies or variety level on the CITES Appendices have been assessed for the Red List.

Among them are two ginsengs, with very different outcomes:

Panax ginseng (Asian Ginseng) – Critically Endangered. Once widespread across forests of China, Korea and Russia, wild populations have been reduced by more than 80% through unsustainable harvest. Today it survives mainly in one region of Russia, with illegal collection still a major concern.
Cistanche deserticola (Desert Ginseng) – Near Threatened. Once thought to be "on the verge of extinction" in the 1980s due to overharvest, this species in northern China and southern Mongolia has benefited from CITES regulation and large-scale cultivation, which have slowed its decline.

A dense spike of pale yellow and white tubular flowers with purple tips emerging from sandy desert ground under a clear sky.

Harvested stems of Cistanche deserticola, a desert plant widely used in traditional medicine across Asia. Sustainable harvesting practices are critical to conserving wild populations of this ecologically important species. © Chris Thorogood

Several dried, cylindrical stems of a desert plant laid out on sandy ground with people working in the background.

The striking inflorescence of Cistanche deserticola emerging from arid desert sands. This parasitic plant, known for its medicinal value and ecological resilience, thrives in some of the harshest dryland environments on Earth. © Chris Thorogood

These contrasting cases show how Red List data, used alongside CITES regulation, can reveal whether conservation measures are working - or where urgent action is still needed.

Assessing the plants of Itremo massif at Kew Madagascar

The Kew Madagascar team have made substantial contributions to Kew’s Red Listing efforts across more than a decade.

Several white and pale yellow star-shaped orchids with long spurs growing among glossy green leaves in a humid forest.

Elegant white and pale yellow blossoms of Jumellea ibityana grow on mossy branches in Madagascar’s Itremo Massif. This endemic orchid is assessed as Endangered on the IUCN Red List and is a flagship species for forest conservation in the region. ©

A flowering shrub with bright pink and purple blossoms and textured green leaves, growing in sunlight beside a stream in Madagascar.

Vibrant pink blooms of Gravesia pterocaulon light up the forest edge of Madagascar’s Itremo Massif. This endemic Melastomataceae shrub is assessed as Endangered on the IUCN Red List due to its restricted habitat and fragmentation. © RBG Kew

Several white and pale yellow star-shaped orchids with long spurs growing among glossy green leaves in a humid forest.

One of the locally endemic, threatened species is Amphorocalyx rupestris, known from the Central Highlands of Madagascar. It's assessed as Endangered due to habitat loss caused by artisanal mining and uncontrolled fire F.Rakotonasolo © RBG Kew

Brilliant orange blooms of Cynorkis cinnabarina brighten the grassy margins of a high-altitude wetland in Madagascar’s Itremo Massif. This endemic orchid is listed as Vulnerable on the IUCN Red List. © RBG Kew

In the October 2025 update, the first 88 assessments were published from the Today’s Flora for Tomorrow project, which aims to assess all the native plant species occurring in the Kew-managed Itremo Massif Protected Area in central Madagascar.

Rolling grassy hills with scattered shrubs and patches of forest under a clear blue sky in Madagascar’s central highlands.

A view across the Itremo Massif in Madagascar’s central highlands, showing a mosaic of open grasslands and forest patches that support a rich diversity of endemic plant species. © RBG Kew

The assessments in this update are the first to publish among several hundred plants validated by the Kew Madagascar team alongside members of the IUCN SSC Madagascar Plant Specialist Group. The extinction risk assessments for the Today’s Flora for Tomorrow Project have been led by team members Velosoa Razafiniary and Andry Ny Aina Ary Misa.

Last year Henintsoa Razanajatovo became the first Kew Madagascar staff member to qualify as a certified IUCN Red List trainer. Velosoa will attend the 2025 training at IUCN in Cambridge at the start of November 2025, helping to further consolidate assessment expertise at Kew Madagascar and lay the foundations for future in-country training initiatives.

Itremo Massif grassland and woodland landscape, Madagascar

The striking red lateritic hills of Madagascar’s Itremo Massif reveal ancient geological formations and unique habitats that support many endemic and threatened plant species. © RBG Kew

Identifying Tropical Important Plant Areas

The Tropical Important Plant Areas (TIPAs) programme identifies sites for preserving plant diversity in tropical regions. The presence of threatened species is one of three criteria for TIPAs selection, along with botanical richness and threatened habitats. Designation of TIPAs can then enable national authorities to prioritise their protection and sustainable management, supporting the globally threatened species and habitats.

The plateau is covered in rinforest

The slopes of the Benna Plateau covered in rain forest. Credit: X.M. van der Burgt/RBG Kew.

The TIPAs programme is active across the tropics with country projects undertaken across Africa (Cameroon, Ethiopia, Guinea, Mozambique, Sierra Leone, Uganda), Asia (Indonesia), and the Americas (BVI, Turks and Caicos). Especially well-represented in this IUCN Red List update is the TIPAs Bolivia project with nearly 200 assessments published, mostly for species only known from this megadiverse country.

Hippeastrum mollevillquense is a bulbous geophyte growing in interandean dry valleys. Species in this genus are much loved ornamentals, particularly at Christmas, yet in the wild they are threatened by habitat degradation due to agricultural and urban expansion, and as a result this species is assessed as Endangered.

Hippeastrum mollevillquense

Hippeastrum mollevillquense is a much loved ornamental, particularly at Christmas, yet in the wild it is threatened by habitat degradation © Margoth Atahuachi

Preparing Conservation Action Plans for Jamaica's Threatened Plants

Following a successful Red List training workshop hosted in Jamaica (funded by CEPF) and led by our assessment team members, over 100 assessments were completed in collaboration with newly trained assessors from the University of the West Indies and Institute of Jamaica.

The Red List assessment data generated fed directly into a subsequent Conservation Action Planning workshop held by IUCN Conservation Planning Specialist Group.

A small epiphytic orchid with slender green leaves and tiny orange flowers growing on lichen-covered tree bark in a forest.

Jamaican endemic Andreettaea delicatula, assessed as Vulnerable © Alan Franck

A tall palm with arching green fronds and a slender trunk, photographed from below against a blue sky.

Least Concern Calyptrogyne occidentalis in Mason River Nature Reserve, Jamaica. © Vida Svahnström

A cluster of small creamy white orchid flowers with yellow centres growing on a thin stem in a forest clearing.

Least Concern orchid Epidendrum verrucosum; widespread across Central America, Mexico and Jamaica. Photo credit: Hermes Vega

Tall palms with smooth grey trunks and large green fronds spreading against a bright sky.

Endangered palm Roystonea princeps © Jean-Paul Boerekamps, accessed via iNaturalist

Bringing together Red Listing and Conservation Action Planning helps to close the gap between recognising that a species is threatened and taking steps to protect it. This integration can reduce the risk that highly threatened species disappear before conservation measures are in place.

A good example is the Endangered palm Roystonea princeps, a distinctive species of swamp forest in the Black River Morass – a Ramsar wetland of international importance. Here, fires, logging and agricultural expansion have destroyed much of its specialised habitat, with more than half of the wild population thought to be lost.

As a result of the recent Conservation Action Planning workshop, one key recommendation was to include the Black River Great Morass wetlands within a protected area corridor.

Red Listing and seed conservation

In recent years, the assessment team have collaborated closely with the Millennium Seed Bank Partnership to complete Red List assessments as part of two global programmes: the Global Tree Seed Bank programme and the Threatened Biodiversity Hotspots Programme. Through the former, Red List assessments have recently been completed for all of Thailand’s endemic tree species, with many appearing on the Red List in the October update.

Wrightia poomae, recently described to science

Wrightia poomae, recently described to science, is known from a single tree in Huai Nam Khao Forest. Its seeds have been banked through the GTSB project. It is assessed as Data Deficient, with further conservation work needed © Naiyana Tetsana / RBG Kew

The results of the Red List assessments are helping to guide conservation practitioners and policymakers in Thailand in planning in situ and ex situ conservation actions, including establishment of new protected areas and precise targeting of future seed collection missions. It’s a great example of a conservation-positive feedback loop – Red List assessments help in prioritisation of seed collection efforts which improve the ground-truthing and data availability for Red List assessments which permit further refinement of seed collection prioritisation.

The broader impact

Kew’s mission is to halt biodiversity loss. But we can only take effective steps towards this goal if we know which species are most at risk, in which ecosystems they occur, and which threats need to be mitigated to allow them to recover. Relative extinction risk represents a critical conservation baseline.

Recent publications led by the Conservation Assessment & Analysis Team predict that around 45% of vascular plant species are threatened with extinction, with this figure increasing to about 75% threatened for the large but as yet unquantifiable number of plant species that remain undescribed to science.

A pale yellow, star-shaped orchid with long, narrow petals growing on the bark of a tree in a forest canopy.

An epiphytic orchid, Angraecum popowii, displays its characteristic long-spurred flowers on a mossy tree trunk in Madagascar’s humid forest. Endangered orchid threatened by fires set for grazing renewal © RBG Kew

This context-setting is crucial to guide overall conservation strategy, but it is detailed individual assessment information that translates most directly into conservation action for a threatened species.

As of October 2025, only around 20% of plants and less than 1% of fungi have an extinction risk assessment. We are taking positive steps towards addressing knowledge gaps in species extinction risk but there remains much to be done.

Through working together on Red List assessments, we can raise the profiles of our plants and fungi and help to bend the curve of plant and fungal diversity loss.

Acknowledgements

Funders

For further information on who funded the projects mentioned in this blog, please follow the links in the copy that will take you to there respective project pages where you'll be able to learn more about who funded the project.

Additional contributors to the blog

Amy Barker, Emma Williams, Vida Svahnström, Bente Kiltgaard, Maira Martinez, Velosoa Razafiniary, Nivohenintsoa Rakotonirina, Andry Rakotoarisioa, Kate Hardwick, Voradol Chamchumroon, Oriana Lino, Liliana Arroyo.

Assessment list

Kaewmuan, A., Tran, V.T., Lowry II, P.P., Middleton, D., Henderson, A., Hul, S., Cheng, S.K., Diep, T.M.H. & Phan, K.L. 2025. Wrightia sirikitiae. The IUCN Red List of Threatened Species 2025: e.T191073A1969244. Accessed on 16 October 2025. https://www.iucnredlist.org/species/191073/1969244

Barker, A. 2025. Panax ginseng. The IUCN Red List of Threatened Species 2025: e.T18788264A83997323. Accessed on 16 October 2025. https://www.iucnredlist.org/species/18788264/83997323

Bevan, H. 2025. Cistanche deserticola. The IUCN Red List of Threatened Species 2025: e.T201595A214342747. Accessed on 16 October 2025. https://www.iucnredlist.org/species/201595/214342747

Rajaovelona, L.R. & Ravololomanana, N. 2025. Jumellea ibityana. The IUCN Red List of Threatened Species 2025: e.T65611947A66172894. Accessed on 16 October 2025. https://www.iucnredlist.org/species/65611947/66172894

Razafiniary, V. 2025. Gravesia pterocaulon. The IUCN Red List of Threatened Species 2025: e.T223201806A223202220. Accessed on 16 October 2025. https://www.iucnredlist.org/species/223201806/223202220

Andry Ny Aina, A.A.M. 2025. Amphorocalyx rupestris. The IUCN Red List of Threatened Species 2025: e.T218342748A218344238. Accessed on 16 October 2025. https://www.iucnredlist.org/species/218342748/218344238

Razafiniary, V. 2025. Cynorkis cinnabarina. The IUCN Red List of Threatened Species 2025: e.T44392752A103493390. Accessed on 16 October 2025. https://www.iucnredlist.org/species/44392752/103493390

Atahuachi, M., Lino Villalba, O. & Lara Rico, R. 2025. Hippeastrum mollevillquense. The IUCN Red List of Threatened Species 2025: e.T224170146A224961952. Accessed on 16 October 2025. https://www.iucnredlist.org/species/224170146/224961952

Svahnström, V. 2025. Andreettaea delicatula. The IUCN Red List of Threatened Species 2025: e.T256817168A257325651. Accessed on 16 October 2025. https://www.iucnredlist.org/species/256817168/257325651

Svahnström, V. 2025. Calyptrogyne occidentalis. The IUCN Red List of Threatened Species 2025: e.T201631A2709621. Accessed on 16 October 2025. https://www.iucnredlist.org/species/201631/2709621

Svahnström, V. 2025. Epidendrum verrucosum. The IUCN Red List of Threatened Species 2025: e.T256833097A257325501. Accessed on 16 October 2025. https://www.iucnredlist.org/species/256833097/257325501

Middleton, D., Pooma, R. & Kaewmuan, A. 2025. Wrightia poomae. The IUCN Red List of Threatened Species 2025: e.T191817A2006144. Accessed on 16 October 2025. https://www.iucnredlist.org/species/191817/2006144