UK: World's smelliest flower blooms at the Botanic Garden

Visitors are flocking to the Royal Botanic Garden Edinburgh (RBGE) to see a giant Amorphophallus titanum (titan arum), which is the world’s smelliest flower, in full bloom.

The plant, also known as the “corpse flower’’ because it emits a stench like rotting flesh to attract pollinating insects, is flowering for the second time in two years.

When it flowered in June 2015 around 19,000 people visited the Lowland Tropics House to see the first flowering of an Amorphophallus titanum in Scotland.

This time round the plant will be pollinated, and if it successfully fruits, the plant will most likely die after completing its natural life cycle. It is predicted the flower will last one or two days.

Scientists at RBGE are studying the Amorphophallus titanum to find out more about its pungent small and what pollinators it attracts.Dr Peter Wilkie, a Tropical Botanist at RBGE explained: “The last time the Amorphophallus titanum flowered we studied its morphology and structure, this time we want to better understand its biology. We want to investigate how it produces its famous smell, what pollinators are attracted to the smell and what animals disperse its seed. We are also keen to investigate why several plants are flowering in different parts of the world at the same time - are there particular environmental triggers? Are the plants that flower at the same time very closely related genetically? For such an iconic plant there is so much we don’t yet know.''



Explaining the scientific significance behind the plant, Tropical Botanist Mark Hughes said: “The titan arum grows only on the Indonesian island of Sumatra, and its flowering here in RBGE for the second time symbolises our research and conservation efforts in that country. We have another 440 species of plants in our Glasshouses from Indonesia, many of them incredibly rare and endangered but also fascinating and beautiful. In the past five years our scientists have described over 50 new species from Indonesian forests, showing how much remains to be discovered and protected for the future.’’

The titan arum is a giant among plants, with a massive flowering structure that rises some three metres above the ground. A single leaf can reach a height of six metres and a spread of five metres and looks like a small tree rather than the herbaceous plant that it actually is. Its flowering is rare and unpredictable. The flower emits the pungent smell to attract pollinating insects such as carrion beetles and flies.

Successfully bringing the titan arum to the point of flowering has involved replicating the conditions it would experience in the rainforests of Sumatra. The Lowland Tropics House provides the required high humidity and temperatures. During the day the temperatures are between 21-25 degrees centigrade, and by night above a minimum of 19 degrees centigrade with about 80% humidity. The 1,000 litre pot is watered with a high potash liquid fertiliser (Tomato Food) and care is taken to avoid waterlogged conditions as this could cause the corm to rot.

In 2010 staff at the Garden had to borrow scales from Edinburgh Zoo to weigh the corm which at an impressive £153.9kgs, smashed the existing world record of 117kgs, held by Bonn Botanic Gardens, Germany, by 36.9kgs. At the time of the weigh in it had grown from the size of an orange to measuring 952mm wide and 426mm high with a circumference of 280cm.

More work is needed to establish the conservation status of titan arum in the wild. It is currently only known from the Bukit Barisan range of mountains in West Sumatra and is classified as Vulnerable (V) on the 1997 International Union for Conservation of Nature (IUCN) Red List of Threatened Plants.

Sumatra is part of RBGE’s ongoing research in Southeast Asia on diverse tropical plant families including the Zingiberaceae (gingers), Begoniaceae (begonias), Gesneriaceae and tropical trees in the Sapotaceae and Malvaceae.

For more information:
www.rbge.org.uk