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An On-line Version of an Aquatic Plant Identification Manual for Washington's Freshwater Plants Sensitive, Threatened, and Endangered Species
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Scientists
estimate there are more than 3,500 different vascular plants native to Washington.
This botanical diversity is the result of evolution over the
millennia. Although extinction is a
natural process, in modern times this process has occurred at an
accelerated rate. The major current
cause of extinction is the widespread elimination or disturbance of native
habitats by humans. With the loss of
plant diversity, we lose parts of ecosystems that might be vital to the
balance of nature. The loss of such
biological diversity is currently a major national and international
concern.
The federal Endangered Species Act requires conservation of threatened and endangered species. In Washington, the Department of Natural Resources Natural Heritage Program (WNHP) maintains data on three categories of rare plants: endangered, threatened, or sensitive (WNHP, 1994). Endangered plants are defined as those in danger of becoming extinct in Washington within the foreseeable future. Threatened plants are generally those likely to become endangered in Washington. Sensitive plants are those that are vulnerable or whose populations are declining, and which could become endangered or threatened without active management or protection. Of Washington's approximately 3,500 species, 18 have become extinct or eliminated from the state since about 1850 and approximately 240 species are presently considered to be endangered, threatened, or sensitive (WNHP, 1994). Most rare plants occupy environments such as rock outcrops, unusual soils, wetlands, and aquatic habitats. This manual includes identification information for two rare species that are found in aquatic and wetland habitats: water lobelia (Lobelia dortmanna), considered threatened in Washington and blunt-leaved pondweed (Potamogeton obtusifolius), which is considered sensitive in Washington. There are several additional aquatic and wetland plants listed as rare which are not included in this book. For a complete listing contact the WNHP. The ability to recognize these and other rare plants may help prevent their unintentional loss resulting from aquatic plant management activities and shoreline development. By identifying and protecting these species, we can all protect Washington's botanical heritage for future generations. |
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