Lythrum salicaria

Photo: 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?

CDFA Rating: -*?


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.

Species ID Card

Invasive Species ID Card - To support field identification of early detection species, Cal-IPC has designed a set of Species ID cards that can be downloaded, printed double-sided, and trimmed to size.

Weed Management Notes

  • Management Notes - Information on management techniques and effectiveness from the University of California Cooperative Extension’s Weed Research & Information Center.

Cal-IPC Newsletter Articles

Cal-IPC Symposium Presentations

Presentations are linked where available. Where a presentation is not available, find more information by reading the abstract in the Cal-IPC Symposia Archive.

Other Lythrum salicaria Information

  • Bugwood - National database from the Center for Invasive Species and Ecosystem Health at the University of Georgia.
  • CalPhotos - Images of plants taken mostly in California.
  • Calflora - Distribution map and records of this species in California.
  • CalWeedMapper - Distribution map of this species in California with ability to determine regional priorities.
  • EDDMapS - Distribution of this species in North America.
  • Jepson Interchange - Information on this plant's taxonomy, biology, and distribution from UC Berkeley's Jepson Herbarium.
  • USDA PLANTS Database - Information on identification and distribution, with links to websites in individual states.
  • Additional photos

    Lythrum salicaria_flowers_KeirMorse
    Lythrum salicaria (purple loosestrife) flowers. Photo: Keir Morse
    Lythrum salicaria_leaves and stem_KeirMorse
    Lythrum salicaria (purple loosestrife) leaves and stem. Photo: Keir Morse
    Lythrum salicaria_inflorescence (pre-flower)_copyright2001_DougBarbe(CDFA)
    Lythrum salicaria (purple loosestrife) inflorescence (pre-flower). Photo: &#169 2001 Doug Barbe, CDFA
    Lythrum salicaria_infestation_copyright2001_CarriBenefield(CDFA)
    Lythrum salicaria (purple loosestrife) infestation. Photo: &#169 2001 Carri Benefield, CDFA