1 of 1 Rafflesia arnoldii, one of the endangered species of the genus Rafflesia — Photo: LukeTriton Rafflesia arnoldii, one of the endangered species of the genus Rafflesia — Photo: LukeTriton
An international group of scientists has launched an urgent call for coordinated action to save plants in the Rafflesia genus, which have the largest flowers in the world. The initiative follows a new study published this week that found most of the genus’s 42 species are at serious risk of extinction.
Only one of these genera is listed on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species: Rafflesia magnifica. However, more than twothirds (67%) of plant habitats are unprotected and at risk of destruction, according to the study, published in the journal Plants, People, Planet.
Rafflesia is a parasite that attacks tropical vines in the jungles of Southeast Asia in countries such as Indonesia, Malaysia and the Philippines. For most of its life cycle, it remains hidden from view, existing as a system of filaments that penetrate its host. After some time, the parasite produces a cabbagelike bud that breaks through the bark of the vine, eventually forming a huge fivelobed flower up to a meter in diameter. This creates an unpleasant smell of rotting flesh to attract pollinating flies, earning it the alternative name “corpse flower.”
Due to their unusual life cycle, knowledge of Rafflesia plants is still insufficient and it is believed that new species have not yet been recorded. To better understand the vulnerability of these unique plants, a group of scientists created the first coordinated global network to assess the threats facing Rafflesia.
The results of the study found that all 42 Rafflesia species are threatened: based on IUCN criteria, scientists classified 25 as “critically endangered,” 15 as “endangered,” and two as “endangered.” For this reason, researchers recommend that all Rafflesia species be immediately added to the IUCN Red List of Threatened Species.
“This new study shows that global conservation efforts focused on plants are lagging behind animal conservation efforts. “We urgently need a collaborative, crossregional approach to save some of the world’s most remarkable flowers, many of which are now at risk of extinction,” says Dr. Chris Thorogood, deputy director of the University of Oxford Botanic Gardens and one of the study authors.
Rafflesias have a very limited geographical distribution and are therefore particularly at risk of extinction due to the destruction of the few existing habitats. The study found that many of the remaining populations have only a few individuals left, residing in unprotected areas at risk of conversion to agriculture. Since attempts to propagate Rafflesia in botanical gardens have so far had limited success, protecting the habitat is an urgent priority, scientists emphasize.
The team proposes a fourpoint action plan for governments, research centers and conservation organizations:
- Greater protection of Rafflesia habitats, targeting populations at highest risk. According to the University of Oxford, Southeast Asia has the world’s fastestdisappearing forests, and many of the known Rafflesia populations are dangerously close to growing human settlements.
- Better understanding of the full existing diversity of Rafflesia to support decision making. We can’t protect something we don’t know exists. Therefore, sampling expeditions and genetic analyzes are needed to understand how many Rafflesia species actually exist.
- Develop methods to successfully propagate Rafflesia outside of its natural habitat. This could include grafting Rafflesiainfected vines onto uninfected vines to protect species whose habitat is likely to be destroyed;
- Introducing new ecotourism initiatives to involve local communities in Rafflesia conservation. Raise awareness among local communities and train tourism and conservation leaders to support these efforts.