Dozens of "Red Books" are compiled by state, regional, national, and continental authorities listing threatened or endangered plants or animals of various geographical or political of the world. Now for the first time, the World Conservation Union, in conjunction with the Association for Biodiversity Information, National Botanical Institute, Royal Botanical Garden Edinburgh, Royal Botanical Gardens, Kew, Smithsonian Institution, The Nature Conservancy, The New York Botanical Garden, and Wildlife Australia have produced the first global red list of threatened plants.
This massive collaborative effort took more than 20 years to complete and involved plant biologists and institutions throughout the world. Marking a major publishing event on the literature of threatened and endangered species, the 1997 IUCN Red List of Threatened Plants covers more than 34,000 species from 200 countries. In this, the first global assessment of plants at risk, we learn that an astounding one in eight plant species worldwide (12 percent) are threatened with possible extinction. Of the estimated 270,000 known species of vascular plants, 33,798 are considered at risk of extinction. Ninety-one percent of the threatened 369 plant families are listed. For 20 of those plant families at least half of their species are threatened. More than 6,500 plant species in the list are considered endangered (in imminent danger of extinction). Of the species on the list, 380 are now extinct in the wild.
These staggering numbers, for the first time, place information on threatened species in one reference volume available to all interested in the continued survival of plant species on this small planet. Major reasons for species loss include destruction of habitat as well as the introduction of non-native species, which compete with native plants, eventually overtaking them. Such is the case, for example, with kudzu and Japanese honeysuckle in the southeastern United States.
Perhaps the best-studied country in the world is the United States. With a native flora of some 16,000 species, the number of at-risk species in the United States is more than double the percentage compared with the general global assessment. A full 29 percent of plant species in the United States are listed in the 1997 IUCN Red List of Threatened Plants.
Although the list is the most comprehensive ever compiled, it may only represent the tip of the iceberg. There is a strong regional bias to the compilation. North America, Australia, Western Europe, and South Africa are particularly well-represented in the book, primarily because most plant scientists in those countries have been employed in cataloging and observing rare indigenous species. This trend in plant science research has continued for more than 30 years. Relatively poorly studied areas include most of Africa, Asia, the Caribbean, and South America. Island plant populations are at the greatest risk. Seven of the countries with the highest numbers of threatened species are islands, including St. Helena, Mauritius, Seychelles, Jamaica, French Polynesia, Pitcairn, and Reunion. As much as half of the indigenous flora of the state of Hawaii is also at risk. Expanded collecting in what amounts to the vast majority of the world's land masses over the next few decades will grea tly increase the catalogued numbers of threatened species -- if those plants survive long enough to be counted. Also, the list is limited to vascular plants (ferns, fern allies, conifers, and flowering plants). It does not include lower plant groups such as mosses, liverworts, and algae, nor does it include fungi or lichens. [The reason for this distinction is that fungi are not in any way related to plants, belonging to a separate Kingdom. Lichens are a symbiosis of a fungus and either a cyanobacterium or a green alga (which is a plant).(1)]
The main part of the book, listing of taxa, are arranged by major groups such as fern allies, ferns, gymnosperms, and angiosperms. Within these broad categories, taxa are arranged alphabetically by family, genus, and so forth. Nomenclature follows major regional or continental works over national or state floras. Synonyms, unfortunately, are excluded. This information exists in the database used to compile the work, but was apparently not included due to space considerations. Data on status (threatened, endangered, or extinct) is coded into each record, along with the geographical region of origin and a numerical entry corresponding to a specific reference in the extensive 70-page bibliography that includes thousands of references. These data sources contain extremely valuable information for those seeking more details on a particular plant group or taxon. Three appendixes are included with information on the IUCN Red List Categories; Threatened Plants Database Management infor mation; and Rankings by The Nature Conservancy and Wildlife Australia status ranks. Thirteen tables with information on various statistical break-outs and other data are included.
This is a massive effort, resulting in a starting point for bringing the important, no, vital issue of plant extinction to the forefront. What is the significance for medicinal plant species, or potential new drug sources? For instance, 75 percent of the species from the yew (Taxaceae), a source of important cancer-fighting compounds, are threatened. The willow family (Salicaceae), from which aspirin is derived, has 12 percent of its species threatened. Aspirin has never been derived from the willow family, and its precursor salicylic acid was first discovered and derived from the rose family (Rosaceae), but you get the point. Four of the nine species of Echinacea are included on the list as well. This is a landmark reference tool that should be in the hands of everyone in the field of economic botany (which includes the majority of readers of HerbalGram).
(1) Marles, Robin. 1999. January. Personal communication.
Article copyright American Botanical Council.
By Steven Foster