Real potential comes to Scotland for saving Rafflesia

It is the world’s largest flower and the one that botanic gardens around the globe have ambitions to cultivate. But, for now at least, the only Rafflesia arnoldii accessible to the Royal Botanic Garden Edinburgh (RBGE) is the model kindly on loan from National Museums Scotland - to boldly raise awareness of serious conservation concerns.

Under the banner Flora Malesiana 10: Classify Cultivate Conserve, more than 100 leading scientists, horticulturists and conservationists are in Edinburgh to share knowledge and develop new skills essential to saving habitats under threat from human activity and climate change. Centre stage to it all is this glorious Rafflesia.

The loan is a demonstration of partnership between the two Scottish organisations – both recipients of funding from players of People’s Postcode Lottery – following their signing of a formal Memorandum of Understanding.

While a plant with no leaves, stems or true roots sounds like the stuff of comic books or science fiction, the facts behind it are only too real, as RBGE Glasshouse Supervisor and tropical plant expert Louise Galloway explained: “We are incredibly lucky to have this replicate on loan from the National Museums Scotland. Rafflesia arnoldii grows in primary and disturbed forest up to 1000m elevation in the rainforests of Sumatra and Borneo in SE Asia and is under threat through habitat destruction. However, growing this plant in cultivation is notoriously difficult as it is parasitic and requires a particular species of vine and for that vine to be infected. Horticulturists, taxonomists and conservationists will be discussing some of these issues and how we can bring these endangered plants into cultivation, primarily for conservation but also to help engage the wider public with these truly amazing plants.

“One day we hope to attempt to cultivate a Rafflesia arnoldii in Scotland and Flora Malesiana is bringing scientists and horticulturists from all over the world to share ideas and growing techniques for many different groups of plants from that region.”

At over one metre in diameter and up to 10kgs in weight, the giant Rafflesia arnoldii is one of the plant kingdom’s most unusual specimens. With no leaves, stems or true roots, it grows as a parasite within vines of the genus Tetrastigma (Vitaceae – grape family), growing undetected through the tissue of the vine for several years before breaking through the bark of its host as buds. Only a few of these buds survive. However, the successful few swell over several months finally bursting into giant five-petalled fleshy brownish-red and cream mottled flowers: something of an otherworldly appearance. The flowers are either male or female, but both look the same, and smell like rotting flesh, giving rise to the common name of corpse or meat flower to attract carrion flies which transport the pollen from male flowers to female flowers. They are very short-lived, lasting up to seven days before collapsing. If pollination is successful, it is thought that the resultant fruits are eaten by tree shrews and other forest mammals which subsequently disperse the seeds. 

Dr Peter Wilkie, tropical botanist and organiser of Flora Malesiana10 at RBGE added: ““We know very little about the biology of these species and it is great to have scientists from Indonesia, Malaysia and the Philippines who work on these iconic plants come to RBGE to discuss their research findings.  At a time when we are learning important new things about other planets and our solar system it is worth reminding ourselves that we still have much to discover and understand about the plants growing on our own planet and on which all humanity depends.”

Speaking of his support, Dr Andrew Kitchener, Principal Curator, Vertebrate Biology, National Museums Scotland concluded: “Last year, along with the Royal Zoological Society of Scotland we signed a Memorandum of Understanding with the Royal Botanic Garden Edinburgh (RBGE) underlining our commitment to greater joint working. This agreement builds on our existing relationship, strengthening our longstanding association and bringing greater opportunities for collaboration through academic research and public programmes. Such collaborations maximise our research opportunities and enable us to create engaging public programmes for the benefit of everyone.

“This year we have been working on several joint research and collections improvement projects. These have included plant and animal parasite/host interactions and it is only natural that we extend these collaborations into education and outreach programs.

 “We are delighted to lend our model of Rafflesia, to the RBGE for display during the Flora Malesiana conference and hope that the model will add a colourful additional stimulus for discussion during the symposium, without any of the unfortunate aroma of the world’s largest living flower.”

The Royal Botanic Garden Edinburgh is a charity (registration number SC007983)