The California condor, the Maryland darter, the Florida panther and other animals struggling to survive are not the only endangered species. Largely because of man's encroachment, many, perhaps dozens of American plant species are disappearing each year. Indeed, botanists estimate that some 3,000 of the 22,000 species of higher plants native to the U.S. may be facing extinction. Around the world, as many as 40,000 plant species are in trouble.
Now help is on the way, at least for America's vegetation, in the form of the Center for Plant Conservation, which has its headquarters at Harvard University's Arnold Arboretum. With seed money of $500,000, the center has begun an unprecedented program, by far the most comprehensive to date, that aims to preserve every kind of threatened plant in the U.S.
Through a network of 18 affiliated botanical gardens and horticultural research facilities in 14 states, the center this summer coordinated the collection of 92 threatened species, including such exotic plants as the pygmy fringe tree and Gray's lily. It plans to at least double that number next year and hopes to have specimens of most of the nation's endangered plants secured in greenhouses and other protected environments within ten years.
As added insurance, the center will stockpile seeds of some of the species at the Department of Agriculture's Fort Collins, Colo., seed-storage facility. That way, says Frank Thibodeau, the center's scientific director, "despite power losses, hurricanes, fires or any other natural disaster that could befall a greenhouse or garden, we will always have the seeds available for study and propagation."
By growing these rare plants, the center expects eventually to reintroduce some into their natural habitats and to satisfy the needs of both researchers and collectors. The collectors, oddly enough, have contributed to the near extinction of several species. One victim is the Knowlton cactus, the first endangered species cataloged by the center. Says Donald Falk, the center's administrative director: "Collectors will go out and decimate populations, uprooting the cactus to send it back to live on windowsills."
Why spend money and energy to save, say, the frostweed or the small whorled pogonia? Medical benefits alone, says Thibodeau, could justify the center's efforts: "Well over a quarter of all prescription medicines in the U.S. are based on plant products." He points, for example, to antitumor alkaloids found in the Madagascar periwinkle that are now used in the treatment of childhood leukemia and Hodgkin's disease. "The question," says Thibodeau, "is whether you're willing to bet that there isn't another important drug out there among those 3,000 plants or whether you're willing to hold the plants long enough to study them."
Then, too, some of the plants may have as yet undiscovered characteristics important to agriculture: for example, resistance to disease or drought. Using new recombinant DNA techniques, scientists look forward to identifying the genes that confer these traits and transferring them from wild plants to crop plants. By preserving the endangered species, says Falk, "we're building a genetic library." Thibodeau considers the library essential "even if it turned out that these plants have no other identifiable value. They would still be worth saving, just as it is worth preserving old manuscripts."