The effects of plant loss extend far beyond agriculture. One in every four medicines prescribed in the United States is based on a chemical compound originally found in a plant. And worldwide some 3.5 billion people in developing countries rely on plant-based medicine for their primary health care. Plants also furnish oils, latexes, gums, fibers, timbers, dyes, essences, and other products we use every day. Rural residents of developing countries depend on plant resources for up to 90 percent of their total material needs.
Many medicinal plants are also in trouble from overharvesting and destruction of habitat.
The bark of the African cherry tree is widely used in Europe for treating prostate disorders, but the medicinal trade has led to severe depletion of the tree where it grows in the highlands of central African countries. Since fewer than 1 percent of all plant species have been screened for bioactive compounds, every loss of a unique habitat and its species is potentially a loss of future drugs and medicines. And traditional knowledge about medicinal plants is declining even faster than the plants themselves. In the bank Until recently, gene banks, botanical gardens, and protected areas have been the first line of defense in maintaining the diversity of plant life. The world's 1,600 botanical gardens, for example, collectively tend tens of thousands of plant species.