eddmapslogo

Status of Invasive Plants in Washington

Total number of exotic species reported: 606

Total number of records in EDDMapS: 23944


Invasive Plants by Category

  • Aquatic - 16 species, 1712 records
  • Conifer Trees - 2 species, 2 records
  • Forbs/Herbs - 372 species, 13014 records
  • Grass or Grasslike - 95 species, 3429 records
  • Hardwood Trees - 43 species, 626 records
  • Shrub or Subshrub - 48 species, 1232 records
  • Vines - 30 species, 1053 records

Top Ten Abundant Invasive Plants (by number of reports)

  1. common yarrow - 1626 reports
  2. cheatgrass - 553 reports
  3. Himalayan blackberry - 425 reports
  4. common St. Johnswort - 399 reports
  5. Eurasian water-milfoil - 380 reports
  6. yellow iris - 307 reports
  7. purple loosestrife - 260 reports
  8. Canada thistle - 255 reports
  9. foxglove - 248 reports
  10. bull thistle - 246 reports

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

  1. Canada thistle - 39/39 (100%)
  2. bull thistle - 39/39 (100%)
  3. common yarrow - 39/39 (100%)
  4. field bindweed - 39/39 (100%)
  5. common St. Johnswort - 39/39 (100%)
  6. oxeye daisy - 38/39 (97%)
  7. reed canarygrass - 38/39 (97%)
  8. spotted knapweed - 37/39 (95%)
  9. Japanese knotweed - 37/39 (95%)
  10. diffuse knapweed - 37/39 (95%)

Counties with the most invasive species reported

  1. King County - 479 species
  2. Klickitat County - 386 species
  3. Whitman County - 355 species
  4. San Juan County - 339 species
  5. Okanogan County - 311 species
  6. Pierce County - 292 species
  7. Walla Walla County - 290 species
  8. Whatcom County - 282 species
  9. Spokane County - 279 species
  10. Pend Oreille County - 272 species

Counties with the least invasive species reported

  1. Douglas County - 106 species
  2. Franklin County - 116 species
  3. Garfield County - 139 species
  4. Lincoln County - 141 species
  5. Mason County - 153 species
  6. Adams County - 155 species
  7. Grant County - 163 species
  8. Wahkiakum County - 176 species
  9. Jefferson County - 178 species
  10. Grays Harbor County - 178 species

Report created on November 24, 2014 at 12:08 AM by the UGA Center for Invasive Species and Ecosystem Health using EDDMapS Technology and Data.