Status of Invasive Plants in Oregon

Total number of exotic species reported: 598

Total number of records in EDDMapS: 233907


Invasive Plants by Category

  • Aquatic - 14 species, 5658 records
  • Conifer Trees - 1 species, 1 records
  • Forbs/Herbs - 369 species, 163644 records
  • Grass or Grasslike - 100 species, 13853 records
  • Hardwood Trees - 32 species, 911 records
  • Shrub or Subshrub - 39 species, 40971 records
  • Vines - 29 species, 4298 records

Top Ten Abundant Invasive Plants (by number of reports)

  1. Canada thistle - 23484 reports
  2. Scotch broom - 22066 reports
  3. common St. Johnswort - 18153 reports
  4. bull thistle - 16451 reports
  5. Himalaya blackberry - 15955 reports
  6. tansy ragwort - 14190 reports
  7. yellow starthistle - 11581 reports
  8. Japanese knotweed - 9034 reports
  9. rush skeletonweed - 8447 reports
  10. diffuse knapweed - 6830 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. Multnomah County - 409 species
  2. Lane County - 387 species
  3. Marion County - 369 species
  4. Benton County - 359 species
  5. Jackson County - 359 species
  6. Douglas County - 344 species
  7. Curry County - 301 species
  8. Umatilla County - 277 species
  9. Josephine County - 275 species
  10. Linn County - 272 species

Counties with the least invasive species reported

  1. Gilliam County - 117 species
  2. Sherman County - 140 species
  3. Columbia County - 148 species
  4. Wheeler County - 153 species
  5. Tillamook County - 174 species
  6. Deschutes County - 175 species
  7. Crook County - 178 species
  8. Baker County - 185 species
  9. Morrow County - 188 species
  10. Grant County - 192 species

Report created on April 19, 2014 at 01:09 AM by the UGA Center for Invasive Species and Ecosystem Health using EDDMapS Technology and Data.



Bugwood Center Developed by The University of Georgia - Center for Invasive Species and Ecosystem Health.
Last updated on Tuesday, December 04, 2012 at 08:59 AM