Exotic pest plant species present in the
      region but not currently known to occur
      in the Redwood National and State Parks

Family             Scientific Name                Common Name

ASTERACEAE         Centaurea diffusa              Diffuse Knapweed

LYTHRACEAE         Lythrum salicaria              Purple Loosestrife

Whenever possible, prevention is the most effective and cost-effective control. Invasive plants on a "Watch List" are scrutinized as intensively as if they were inside the park. RNSP works closely with federal, state, and local partner organizations to identify plant species that are invasive and to map individuals and populations where found.

http://www.nps.gov/redw/epwatch.htm
Last Update: April 30, 2002