The World Conservation Union, concluding a 20-year research effort, said in a report Wednesday that 12.5 percent of the world's seed-producing plants and ferns, nearly 34,000 species in all, are in jeopardy of extinction.
"The bottom line is, if you want to eat you'll pay attention to plant conservation," said Brian Boom, vice president of the New York Botanical Garden. Protecting native plants, he said, "is our insurance policy for the future."
"We need protected areas for threatened species, we need areas that are managed in such a way that threatened plants and others can coexist," said Deborah Jensen, director of conservation science for the Nature Conservancy.
"The crucial thing is knowing. If you don't know what you've got, you don't know what's threatened. That's what this book is all about," added Robert Fri, director of the Smithsonian Institution's national Museum of Natural History.
The problem is greater in some regions than others, the researchers said. In the United States, which they say is the most thoroughly studied country, some 29 percent of plants, or 16,000 species, are at risk of extinction.
"Here in Washington we are in the middle of our annual Cherry Blossom Festival. Yet few of us realize that 14 percent of the species in the cherry family are threatened with extinction," said W. John Kress, chairman of the Botany Department at the Museum of Natural History.
There are two main reasons for the threat, Nature Conservancy President John C. Sawhill said in a statement: loss of habitat and competition from the introduction of non-native species.
Overall, the report said, of 270,000 species of vascular plants, 33,798 species in 200 countries are threatened. Some 91 percent of the endangered plants are found only in a single country, a limited distribution that makes them more vulnerable.
On a lonely hilltop on the island of Mauritius, for example, the last stand of Elaeocarpus bojeri holds out, its fruit eaten by a colony of monkeys, its territory overrun by the strawberry guava introduced from Brazil. E. bojeri is a plant so rare it doesn't even have a common name.
In central Chile deforestation threatens Berberidopsis corallina, a coral plant long used by local Mapuche Indians to make baskets, their primary means of making a living.
In the rose family, 14 percent of species are said to be endangered. In the lily and iris families, 32 percent are in trouble.
"Every nation understands and appreciates its biotic wealth much less than it does its material and cultural wealth. Ironically, it is precisely the biological assets that are most at risk," Boom said.
Many of the threatened plats have medical value, the researchers said. For example, 75 percent of yews, which have cancer-fighting compounds, and 12 percent of willows, from which aspirin was derived, are threatened.
The report, called the Red List of Threatened Plants, was compiled over 20 years of research by scientists, conservation groups, botanical gardens and museums around the world.
By Randolph E. Schmid. 1998 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed