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Map Layer Info

Plant Distribution - Lythrum salicaria, Purple Loosestrife

What this map layer shows:

Where Purple Loosestrife, an invasive plant species, is found, by county.
opens the USDA Natural Resources Conservations Service home page
Background Information
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Purple loosestrife (scientific name: Lythrum salicaria) is considered an invasive plant species. Its displacement of native species in wetlands has led to the loss of suitable habitat for wildlife. The USDA Natural Resources Conservation Service collects information on purple loosestrife and other invasive species in its PLANTS Database. These data are derived primarily by looking at actual plant specimens gathered from several institutions. The PLANTS database includes information on the institution where a specimen resides, the State and county where it was collected, and the year of collection. This information allows an analysis of the spread of noxious weeds over time. However, because a relatively small number of institutions were consulted to build this data set, and due to the general unreliability of county-level distribution data (not all counties have been surveyed with equal effort, not all plant populations have been found, plant populations sometimes disappear, and plants sometimes move rapidly or are misidentified), these data provide only a rough cumulative record of the distribution of this plant.

The Plant Distribution - Lythrum salicaria, Purple Loosestrife database shows county-level distribution of this species in the United States. More detailed information on purple loosestrife is available from the purple loosestrife page in the PLANTS database.

Related Links:

If you download the data of Purple Loosestrife distribution you may also want to download the 2000 County Boundaries data. These two map layers can be used together to create a map of Purple Loosestrife distribution.
Download 2000 County Boundaries