Description:
Abstract: Leafy spurge is considered an invasive species which displaces native vegetation in prairie habitats and fields. This data set portrays the county-level distribution of Euphorbia esula (common name - leafy spurge) in the United States of America. These data come from the U.S. Department of Agriculture (USDA) Natural Resources Conservation Service's PLANTS Database, which is the de facto Federal standard for information about the distribution and nomenclature of U.S. plants.
Purpose: These data are intended for geographic display and analysis at the national level, and for large regional areas. The data should be displayed and analyzed at scales appropriate for 1:2,000,000-scale data. The U.S. Geological Survey assumes no responsibility for the use of these data.
Supplemental_Information: These data are primarily derived from examination of herbarium specimens of leafy spurge gathered from several institutions. The essence of each record is the institution where the specimen resides, the state and county where it was collected, and the year of collection. Thus these data are structured to allow an analysis of the spread of this introduced noxious weed over time. Note that there are hundreds of herbaria in the United States, and a relatively small number were consulted to build this data set. For this reason, as well as the general unreliability of county- level distribution data (not all counties have been surveyed with equal effort, not all populations have been found, populations sometimes disappear, and plants sometimes move rapidly or are misidentified), these data can provide only a rough cumulative record of the distribution of this plant. To create maps that are similar to the maps in the National Atlas <
http://nationalatlas.gov/natlas/Natlasstart.asp>, wdeupht.dbf can be joined to the 2000 county boundaries available from the National Atlas download page, <
http://nationalatlas.gov/atlasftp.html>. For more information on leafy spurge, please see <
http://plants.usda.gov/cgi_bin/plant_profile.cgi?symbol=EUES> and Integrated Taxonomic Information System <
http://www.itis.usda.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=28064>
Keywords:
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: Leafy spurge
Theme_Keyword: invasive species
Theme_Keyword: noxious weeds
Theme:
Theme_Keyword_Thesaurus: LCSH
Theme_Keyword: Euphorbia
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: biota
Theme_Keyword: environment
Theme:
Theme_Keyword_Thesaurus: CUGIR Category
Theme_Keyword: biology
Theme_Keyword: environment
Place:
Place_Keyword_Thesaurus: LCSH
Place_Keyword: New York (State)