TO MOST visitors it is a tranquil green space in the heart of the Scottish capital. Yet from its Inverleith Row base, the Royal Botanic Garden Edinburgh (RBGE) is co-ordinating an international conservation drive not seen since the Victorian era.
From China to Nepal, Chile to Malaysia, the RBGE is helping to preserve some of the world's most rare and endangered flora.
Now, at the behest of the Sultan of Oman, staff there are to establish one of the largest botanic gardens ever created in the Arabian desert.
Renowned for its research and wealth of knowledge on the native flora of Arabia, the RBGE has been asked to help create the garden in Muscat. Some 425 hectares in size, the park's immense geography will be four times that of the Royal Botanic Gardens in Kew, and represents an immense challenge for the RBGE's scientists and architects alike.
They will work in fierce heat, cataloguing some 1,200 species, many of them being discovered for the first time. Meticulously listing them and preserving them, the RBGE scientists will then grow the seedlings in specially designed conservatories before they can be transplanted to the completed garden.
Sabina Knees is only too aware of the daunting work that lies ahead, but she seems to relish the prospect nonetheless.
An RBGE specialist in the flora of Arabia and south-west Asia, she told The Scotsman yesterday of her excitement at being in Oman.
She said: "We've only been here a short time, but we are still finding new species. It's a part of the world that for a long time, was not opened up to visitors, and it can still be difficult getting access to areas, so it's tremendously exciting.
"The flora is growing in very stressful conditions, in temperatures of up to 50C. They are species living right at the upper limit of existence. It's a great challenge.
"The sultan only wants to grow native plants, and we're having to find a way of making sure the conditions inside the garden are cooler than they are outside. It's a great task for the engineers and the architects. This garden will be four times the size of Kew.
"The sultan himself is kept at a distance, although he's clearly a man who knows what he wants. It was his chief officer of conservation who approached us, and we're currently at the schematic stage."
Though the heat of Oman may be a new barrier to overcome, the experts at the RBGE are used to combating inhospitable climates in the name of science and ecological protection.
For instance, one recent project in Katmandu required heads for heights. The scheme involved the transportation of live plants and seeds to the UK in order to document Nepal's abundant flora, and find the best way of preserving the mountainous nation's unique variety of plants.
Such was the rarity of some species involved, they only grow along the branches of tall trees, or on sheer cliff faces. In order to secure a Meconopsis horridula - the blue poppy which is the symbol of the RBGE - a trip up a 4,000-metre crag, aided by a Sherpa, was required.
The story of its ongoing search for exotica is likely to reach a wider audience soon, however. Work is under way on a new multi-million-pound visitor centre which will allow visitors to learn more about the RBGE's environmental work being undertaken worldwide.
Called the Gateway, the 15.7 million centre is expected to open in 2009, and will allow field workers to talk directly to visitors about their efforts.
Perhaps the RBGE's best known work has taken place in China, where botanists have carried out the botanical equivalent of hauling coal to Newcastle.
The scientists have managed to recultivate a plant faced with the threat of extinction, the Rhododendron uvarifolium, which bears bright, pink flowers picked by local girls to wear in their hair.
With only a few dozen bushes remaining on the Yulong Xue Shan - or Jade Dragon Snow - mountain in Yunnan province, south-west China, urgent action was required.
The RBGE, home to one of the world's foremost collections of rhododendrons, thanks to the efforts of the legendary plant hunter George Forrest in the early 20th century, was able to transport the seeds of more than 100 species to Yunnan to form new colonies.
In the meantime, it is Oman which is the most exciting of the RBGE's projects. So too, it is a recognition of the Botanic Garden's fountain of knowledge. Dr David Rae, director of horticulture at RBGE, said the Edinburgh institution's expertise had gone a long way towards the prestigious offer of work in Oman.
He said: "This is an extremely important and prestigious project, and our involvement reflects the RBGE's status as a centre of excellence on the Arabian flora. The extensive research we have done in Arabia forms the bedrock of information on the native flora of Oman.
"We have been involved in developing a horticultural and botanical brief for the plans and we are now working on more detailed design with Madrid-based architects Alatec."
Dr Rae explained that RBGE personnel have already helped with the setting up of a nursery within a garden centre in Oman where plants are being grown in preparation for final planting within the botanic garden, as and when needed.
Work on the garden in Oman is due to be completed in 2010 - heat fatigue permitting - by which time Ms Knees and her colleagues may have met the sultan, Qaboos ibn Said, in person.
Whatever the case, she for one is thankful to the sultan's financial assistance, which will allow the RBGE to continue its conservation work elsewhere in the world.
ROOTS IN HEALTH
STRADDLING both its roles as a tourist attraction and a scientific institution, the Royal Botanic Garden Edinburgh (RBGE) was founded as a medicinal garden in 1670 on a site the size of a tennis court in St Anne's Yard, Holyrood, for the cultivation of medical plants.
Such was its success, the garden moved to the area now occupied by platform 11 at Waverley Station, before going on to Leith Walk, and eventually, in 1820, to its present location in Inverleith Row.
Today, the Garden has satellite sites at Benmore in Argyll, Logan in Galloway, and Dawyck near Peebles. Cumulatively, they are home to the second richest collection of plant species in the world.
It specialises in plants from China, the Himalayas, Arabia, South Africa, Europe and South America.
Since the 19th century it has received public funding, and it is now sponsored by the Scottish Executive Environment and Rural Affairs Department (SEERAD)
The garden has a remit and mission whose origins are detailed in the National Heritage (Scotland) Act 1985.