eddmapslogo

Status of Invasive Plants in Oregon

Total number of exotic species reported: 608

Total number of records in EDDMapS: 243320


Invasive Plants by Category

  • Aquatic - 14 species, 5772 records
  • Conifer Trees - 1 species, 1 records
  • Forbs/Herbs - 379 species, 165151 records
  • Grass or Grasslike - 110 species, 14728 records
  • Hardwood Trees - 33 species, 926 records
  • Shrub or Subshrub - 40 species, 41212 records
  • Vines - 29 species, 4493 records

Top Ten Abundant Invasive Plants (by number of reports)

  1. Canada thistle - 23546 reports
  2. Scotch broom - 22160 reports
  3. common St. Johnswort - 18208 reports
  4. bull thistle - 16532 reports
  5. Himalayan blackberry - 16048 reports
  6. tansy ragwort - 14241 reports
  7. yellow starthistle - 11603 reports
  8. Japanese knotweed - 9047 reports
  9. rush skeletonweed - 8447 reports
  10. diffuse knapweed - 6848 reports

Top Ten Widespread Invasive Plants (by number of positive counties)

  1. Canada thistle - 36/36 (100%)
  2. bull thistle - 36/36 (100%)
  3. redstem filaree - 36/36 (100%)
  4. common yarrow - 35/36 (97%)
  5. common St. Johnswort - 35/36 (97%)
  6. orchardgrass - 35/36 (97%)
  7. soft brome - 35/36 (97%)
  8. soft brome - 35/36 (97%)
  9. curly dock - 35/36 (97%)
  10. curly dock - 35/36 (97%)

Counties with the most invasive species reported

  1. Lake County - 441 species
  2. Multnomah County - 425 species
  3. Lane County - 405 species
  4. Jackson County - 382 species
  5. Marion County - 382 species
  6. Benton County - 369 species
  7. Douglas County - 357 species
  8. Curry County - 314 species
  9. Josephine County - 288 species
  10. Umatilla County - 288 species

Counties with the least invasive species reported

  1. Gilliam County - 125 species
  2. Columbia County - 157 species
  3. Wheeler County - 163 species
  4. Sherman County - 166 species
  5. Deschutes County - 185 species
  6. Tillamook County - 185 species
  7. Crook County - 188 species
  8. Morrow County - 195 species
  9. Baker County - 196 species
  10. Clatsop County - 204 species

Report created on October 31, 2014 at 11:38 PM by the UGA Center for Invasive Species and Ecosystem Health using EDDMapS Technology and Data.