Plants, just like animals, are facing endangerment. Scientists predict that in the next 50 years, 25 percent of the world's quarter-million species of flowering plants could disappear.
Britain's Royal Botanic Gardens is tackling the problem by creating a massive seed bank for conserving plant species under threat worldwide.
Sir Ghillean Prance, director of Kew Gardens (as the Gardens are commonly known), says that without the planned Millennium Seed Bank "there is no doubt that large numbers of plants will continue to become extinct in the wild."
Plant species in certain habitats, such as the margins of deserts and wetlands in temperate areas, are especially vulnerable, says Mr. Prance.
A team of plant specialists - located at Wakehurst Place in Sussex, about 50 miles from London and administered by Kew - has launched a plan to recover and bring to England seeds of thousands of threatened plant species.
The seeds will be dried and stored at subzero temperatures. Carefully classified and tabulated, they will be able to survive for hundreds of years (available, as needed) for reintroduction to the wild or for scientific research.
The initial aim of the Millennium Seed Bank project is to collect representative samples of all Britain's 1,400 seeding plants by the year 2000. Later, by the year 2010, says Roger Smith, a leading member of the Wakehurst team, Kew hopes to have collected a further 10 percent of the world's flora - some 25,000 species - making it the world's largest seed conservation project.
From that point, if funds are available, the seed bank will continue to expand.
An example of a severely threatened British plant species is field cow-wheat (Melampyrum arvense, see photo at top), once commonly found in England on the edges of arable fields and grassy cliffs, but now endangered by intensive farming.
Seeds of this lusty but imperiled plant, with its spiky purple flower, are already stored at Wakehurst Place.
Beyond Britain, initial concentration will be on tropical plants in dry areas, says Mr. Smith.
These parts of the world, though less publicized than the threatened rain-forest regions, are home to a large variety of plants on which people heavily depend for food and for a wide range of other needs.
A typical species now in peril is the Gemsbok bean (Tylosema esculentum - see photo, right), a legume found in flat grassy areas in southern Africa.
Its seeds, roasted by local people, taste like cashew nuts. The tubers, when cooked, are like sweet potatoes. The stems are eaten as a vegetable and are also boiled to make a type of tea. Cattle eat the leaves, and uneaten seeds are threaded to make necklaces.
The Gemsbok bean will live on, in seed form, in a secure refrigerated compartment at Wakehurst Place.
Kew Gardens and its specialists are no strangers to plant conservation. Work on storing seeds began 20 years ago, but the scale of the operation was tiny (some 4,000 seed species are currently held) compared with the planned Millennium Seed Bank.
It was the Rio Earth Summit in 1992, and Britain's subsequent ratification of the Convention on Biological Diversity, that provided the stimulus for the expanded project.
"We were beginning to realize that we were operating on a scale too small compared to the environmental problems we were seeing and the threats to species - especially in the semiarid areas of the tropics where 900 million of the world's population live," Smith says.
"It was crunch time. Either our seed bank operation had to get much bigger, or we had to get out of seed banking altogether."
Creating a greatly expanded seed bank posed a major funding problem. The cost of the project up to 2010 is put at $120 million (76 million) at current prices.
Prance and his colleagues, supported by a team of financial advisers, set about searching for the necessary cash.
Some of it will be provided by the Kew Foundation and Friends of Kew - citizens and companies helping the Royal Botanic Gardens with donations. The Foundation and Friends hope to raise $11 million (7 million).
A larger chunk of money will be provided by the Global Environment Facility created under the Biodiversity Convention. The GEF will pay money directly to countries that take part in the seed-collecting program and send the seeds to Britain for classification and storage.
A crucial cash injection - $34.1 million (21.6 million) - will come from Britain's Millennium Commission, which is funding a range of projects to mark the onset of the 21st century. The commission is financed by the successful National Lottery started two years ago.
WITH this amount of funding already assured, Kew Gardens is about to launch an international appeal aimed at closing the gap between cash already in hand or promised, and the final $120 million (76 million).
Prance and Giles Coode-Adams, chief executive of the Foundation and Friends, planned to travel to the United States this month on a fund-raising mission.
Getting the cooperation of countries where plant species are under threat will be crucial to the success of the Millennium Seed Bank, but Michael Way, a seed collector at Kew, says he expects few problems once the project is up and running.
"A lot of countries are aware of the possibilities and of the biodiversity issues," he says. "They will grasp the opportunities the Millennium Seed Bank offers if they can."
Mr. Way has recently been seed-collecting in Yucatan, Mexico, and expects the first collections for the seed bank to be made in Latin America.
"Genetic resources are a hot issue there, and Kew has a very good history of collaboration with countries such as Mexico and Brazil," he says.
The task Kew Gardens is setting for will still be incomplete when tens of thousands of seed species are labeled and stored in racks at Wakehurst Place.
Robin Probert, a seed scientist at Kew, says the need is not so much for the seeds themselves "but for the plants that the seeds can become." Mr. Probert also says that storing the seeds is only the beginning. "We must ensure we are able to germinate them into plants again."
When seed plant species begin arriving from around the world at Wakehurst Place at an anticipated rate of 10 a day, research will be continuing on how to process them so that later generations can go to the seed bank and be sure that the species they take will flower and flourish.