The Role of the Living Orchid Collection

Epidendrum ilense - seedlings of this endangered orchid have been propagated and distributed by Kew		Temperate orchids in the Princess of Wales Conservatory
J P Gregory

Orchids have been cultivated in the Royal Botanic Gardens, Kew for over two hundred years. The first exotic orchids to flower excited wonder and admiration and orchids remain popular today.

The collection must cater for display and research and this has resulted in the plant collections being divided and housed in separate areas to meet these two needs. This is still the case even though Kew’s role is constantly evolving. The recent mission statement makes our modern role clear:

‘The mission of the Royal Botanic Gardens, Kew is to ensure better management of the Earth’s environment by increasing knowledge and understanding of the plant kingdom - the basis of life on Earth. Our mission will be achieved through worldwide research into plants and the ecosystem, publication, access to all knowledge so gained for the world’s scientific community, and through the display and interpretation to the public of the collections at Kew and Wakehurst Place. Whenever possible, the Royal Botanic Gardens will endeavour to reduce and reverse the rate of destruction of the world’s plant species and their habitats.’

Composition of the collection

The collection currently holds about five thousand species at any one time. This is about 20 per cent of the total number of orchid species. The composition of the collection closely reflects past and current research work. It is, for example, particularly rich in Paphiopedilum and Cymbidium species as these have been the subject of recent monographs. Research into the flora of such regions as East Africa, Borneo and the Pacific Islands has resulted in a rich representation of orchids from these areas in the collection. However, as emphasis in research changes, so the composition of the collection must change to meet new needs which arise. Other parts of the collection have been built up for their display or educational value rather than for research. A number of hybrids, mostly of historic interest, fall within this group and form a popular constituent of displays for the public. The majority of the orchids in the collection are, however, naturally occurring species.

Orchids on display

Part of the orchid collection is on permanent display to the public and is housed in the Princess of Wales Conservatory. This is the newest of Kew’s public glasshouses and contains displays of many important groups of tropical plants such as cacti and succulents, ferns, carnivorous plants and bromeliads. Internally the glasshouse is divided into ten different zones, each one having a different computer-controlled climate. Lowland tropical orchids are displayed in Zone 6, while orchids from higher altitudes and temperate regions occupy Zone 7. Both display areas are landscaped and planted with foliage plants appropriate to each climate.

The way in which the orchids are planted is intended to reflect each species’ natural preference. Some orchids are terrestrial, rooting in various substrates in the ground. Terrestrial species, such as Phaius tankervilleae from South-East Asia, are planted in the beds where they relish the unrestricted root run. Eighty per cent of tropical orchids are, however, epiphytes, growing naturally on the branches of trees. They do not draw nutrients from them but simply use the branches for support. Large branches take the place of forest trees in the display and epiphytic orchids are grown on them. Many, such as Oncidium sphacelatum from Central America, have long flower spikes which arch out into the surrounding space. Some orchid species tend to grow on rocks and these lithophytes are planted on or close to rocks in the display. Paphiopedilum insigne has spread among the crevices in the rocks much as it would do in its native north-eastern India. The main emphasis of the permanent display is educational. It conveys an impression of the ways in which orchids grow in the wild and enables visitors to see the adaptations which have evolved in the orchid family.

A glass screen in each zone demarcates an area of temporary display. Flowering specimens from the reserve collection are shown behind the screens for visitors to enjoy the range of size, shape and colour which orchids exhibit. These displays are often thematic and are accompanied by explanations of various aspects of orchid cultivation, the conservation of rare species or the development of hybrids.

Education

The reserve orchid collection is housed in an area of the nursery which is not open to the public on a daily basis. Education is still an important facet of the work of this part of the collection. Students on the Kew Diploma course are trained in orchid cultivation as they work in the collection, as are international students who come each year from many countries. As orchids become rarer in their natural habitats, the skills of ex situ conservation become more important and many international students pursue conservation-related careers when they return home. Orchid enthusiasts travel to Kew from all over the world and staff arrange regular tours for orchid society members. The collection provides teaching material for occasional courses on aspects of orchid cultivation.

Research and conservation

The collection is used extensively for research both by Kew’s own scientists and visiting botanists. Their subjects range from taxonomy, pollination biology and anatomy to molecular biosystematics and the relationship between orchids and fungi. Aspects of Kew’s research on orchids are covered by information sheets K13, K14 and K15. Much of this work may well benefit the conservation of orchids in the future. In addition a number of activities carried out in the collection are intended to further conservation. Seedlings grown in our micropropagation laboratory are distributed annually to botanic gardens, nurseries, orchid societies and other organisations which have shown a commitment to orchid conservation. Pollinations are made in the collection and seed is distributed on request to growers in many countries. In this way essential stock is provided to ensure that endangered species survive in cultivation. An example is provided by the beautiful orchid Epidendrum ilense which was discovered in an area of felled forest in Ecuador. Only six plants were found and rescued and the offspring of one of these was sent to Kew. Hundreds of seedlings have since been distributed from Kew and the species is now well established in cultivation. It may yet be possible to reintroduce this species to the wild. As orchids beome more threatened in the wild by over-collection and changes in their habitats, Kew’s work is becoming more important because it is essential that every possible opportunity is taken to conserve them.

Visiting the reserve collection

Orchid growers and enthusiasts are welcome to visit the reserve collection. All visitors are guided by staff and tours last approximately one and a half hours. Requests for tours must be made in writing, if possible giving a choice of convenient dates.

To book a visit to the Reserve Collection or to request further information about the work of the orchid collection please write to:
Orchid Unit Manager
Lower Nursery
Royal Botanic Gardens
Kew
Richmond
Surrey TW9 3AB