Plants in peril.

• Author: Mattoon, Ashley
• Position: World Conservation Union's 1997 IUCN Red List of Threatened Plants

At least one in eight of the world's known vascular plant species is under threat of extinction, according to the World Conservation Union's new 7-pound, 800-page 1997 IUCN Red List of Threatened Plants.

The report, released on April 8, 1998, is the first-ever global assessment of vascular plants, which include ferns, conifers, and flowering plants (but exclude mosses, lichens, algae, or fungi). Of the species assessed, nearly 34,000 - 12.5 percent of the 270,000 known vascular plant species in the world - are under threat of extinction. The report is based on two decades of research and collaboration among scientists, conservation organizations, botanical gardens, and museums around the world.

While the reasons behind the decline of plant species can be complex and varied, loss of habitat and the introduction of non-native species are the primary threats. For example, heavy logging of forests in central Chile has reduced the distribution of the coral plant (Berberidopsis corallina) to just a few small groves in the forest. And on the island of Mauritius the introduction of both the strawberry guava plant and monkeys has brought the small tree Elaeocarpus bojeri (a species so rare that it has not been given a common name) quite literally to the brink of extinction as the few specimens that remain cling to the side of a hillside.

Due to insufficient data from some regions, the estimated number of threatened plant species is highly conservative and may well represent "just the tip of the iceberg," the report notes. Countries such as Australia, South Africa, and the...