CHAPTER 18 Safe Substitutes for Endangered Herbs: Plant Conservation and Loss of Our Medicines

THE PROBLEM—WHY YOU NEED TO CARE

The consumer-driven herbal products industry has reached $17 billion in international trade at the time of this writing. No reliable estimates are available for the number of endangered or threatened medicinal plants worldwide, but estimates range from 4160 to 10,000 species (Schippmann, 2002, Vorhies, 2000). Even when plants are not recognized by official conservation bodies as endangered, genetic erosion may be occurring because of diminished populations.

TRAFFIC (Trade Records Analysis of Flora and Fauna in Commerce) India, set up by the World Wildlife Fund (WWF) and the World Conservation Union (IUCN), monitors plant species endangerment and has set goals to correct the problem. TRAFFIC lists 33 plants from the Ayurveda/Tibetan/Unani/Siddha Materia medica as critically endangered and 17 as endangered. In Europe, TRAFFIC lists popular medicinal plants such as arnica, uva ursi, thyme, and licorice. Panax quinquefolius has been exported from the United States since the 1700s and has been regulated under the Convention on International Trade in Endangered Species (CITES) since 1975. Even so, the US Department of Agriculture (USDA) and the US Fish and Wildlife Service have reported a trend toward harvesting smaller and younger roots over the past 15 years.

Although no medicinal plants have become extinct in recent memory, it is believed that the first recorded species to succumb is silphion, a plant prized by Ancient Greeks and rendered extinct about 250 bc, probably because of overharvesting. The reasons for the increasing scarcity of once-common plants are many and include the following:

• The variety of commercially available herbs has diminished since herbs were dropped from official pharmacopoeias, and unpopular herbs are unprotected in the environment—some even depend on human cultivation.

• The United States has no strong traditional medicine culture and relies on scientific discovery, which is slow paced and has popularized very few herbs.

• Laypeople and less experienced herbalists do not know enough to differentiate among the properties listed for various herbs; for instance, they automatically use echinacea as an “immune stimulant” when medicinal mushrooms may be more appropriate in some cases.

• Deforestation and urbanization lead to loss of habitat.

• Unsustainable agricultural practices leave the land unsuitable for natural recolonization.

• Export and trade of some endangered plants have increased.

• Current monitoring and regulation of illegal trade are inadequate.

• Lack of information and scientific support leads to a lack of interest in conservation.

Another reason for concern is that increasingly scarce medicinal herbs have been found adulterated in international trade. Table 18-1 provides a list of these plants (Gladstar, 2000).

TABLE 18-1 Plant Products That Are Commonly Adulterated

Plant in Trade	Common Adulterant
Black cohosh	Baneberry (Actaea spp)
Black haw	Striped maple (Acer pensylvanicum)
Echinacea	Prairie dock (Parthenium integrifolium)
Goldenseal	Oregon grape root
Prickly ash	Bristly sarsaparilla (Aralia spinosa)
Sheep sorrel	Yellow dock leaf
Siberian ginseng	Periploca or Acanthopanax spp
Skullcap	Germander
Slippery elm	Rice flour

The effect of biodiversity loss on local populations may well be incalculable. Schubert (1999) describes a visit to an area of India where poor families could no longer afford a traditional tonic, Withania, for their families. The local wild populations of this plant had all been harvested and sold to the United States and Australia.