Lythrum salicaria

Photo courtesy Bob Case

Common names: purple loosestrife

Lythrum salicaria (purple loosestrife) is a wetland herb (family Lythraceae) that invades scattered freshwater wetlands of northern and central California. Infestations are found in northern California and the San Francisco Bay Area, as well as along rivers in the southern Sierra. It is a hardy perennial that can rapidly degrade wetlands, diminishing their value for wildlife habitat.

Cal-IPC Rating: High

Cal-IPC Assessment

Plant Assessment Form - Information gathered by Cal-IPC on the impacts, rate of spread, and distribution of invasive plants in California. Does not include management information.

Cal-IPC Newsletter Articles

Cal-IPC Symposium Presentations

  • Benefield, C. (2000). Preventing the purple plague from taking over California's waterways. California Exotic Pest Plant Council Symposium 2000. Concord, CA.
  • Benefield, C. B. and D. Butler (2001). Purple loosestrife under siege in California. California Exotic Pest Plant Council Symposium 2001. San Diego, CA.
  • Blossey, B. (1996). The search for patterns or what determines the increased competitive ability of invasive non-indigenous plants? California Exotic Pest Plant Council Symposium '96. San Diego, CA.
  • Brown, W. Y. and A. G. Brown (1998). Campaign against invasive species: A call for action. California Exotic Pest Council '98 Symposium. Ontario, CA.
  • Butler, D. and S. Schoenig (2002). Preventing the purple plague from taking over California's wetlands. California Exotic Pest Plant Council Symposium 2002. Sacramento, CA.
  • Chornesky, E. A. and C. M. Palmer (1995). Use of biologically based methods to control pest plants:Issues related to federal research, regulation, and implementation. Proceedings California Exotic Pest Plant Council Symposium '95. Pacific Grove, CA.
  • DiTomaso, J. M. (2005). Efficacy and safety of new herbicides on the horizon. California Invasive Plant Council Symposium 2005. Chico, CA.
  • Donaldson, S. G. (1997). Flood-borne noxious weeds: Impacts on riparian areas and wetlands. California Exotic Pest Plant Council Symposium '97. Concord, CA.
  • Westbrooks, R. G. (1995). Federal regulatory efforts to minimize the introduction and impacts of exotic pest plants in the United States. CalEPPC Symposium '95. Asilomar, CA.
  • Westbrooks, R. G. (2001). Invasive species, coming to America: New strategies for biological protection through prescreening, early warning, and rapid response. California Exotic Pest Plant Council Symposium 2001. San Diego, CA.

Other Lythrum salicaria Information

  • CalPhotos - Images of plants taken mostly in California.
  • CalFlora - Distribution information based on submitted observations and herbarium specimens.
  • CalWeedMapper - Distribution information with ability to determine regional priorities.
  • Jepson Online Interchange for California Flora - Information on taxonomy, biology, and distribution from UC Berkeley's Jepson Herbarium.
  • USDA PLANTS Database - Federal database with information on identification and distribution, and links to websites in individual states.