Eichhornia crassipes

Eichhornia_crassipes_ by By Wouter Hagens
Photo by Wouter Hagens

Synonyms: Eichhornia speciosa, Heteranthera formosa, Piaropus crassipes, Pontederia crassipes

Common names: water hyacinth

Eichhornia crassipes (water hyacinth) is a floating freshwater perennial (family Pontederiaceae) that jams rivers and lakes with tons of floating plant matter. Floating mats of this plant can weigh up to 200 tons per acre. In California, Eichhornia crassipes typically is found below 660 feet (200 m) elevation in the Central Valley, San Francisco Bay Area, and south coast.

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.

Weed RIC 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

  • Brusati, E. (2009). The cost of weeds to California. Cal-IPC News. 17: 6,7,13.
  • Blair, C. E. (2009). Invasive aquatic weeds: Implications for mosquito and vector management activities. Cal-IPC Symposium 2009. Visalia, CA, California Invasive Plant Council.
  • Shruti, K., M. J. Santos, et al. (2008). Patterns of change in water hyacinth distribution in the Sacramento-San Joaquin Delta. California Invasive Plant Council Symposium 2008. Chico, CA, California Invasive Plant Council.
  • Anderson, L. (2003). Aquatic weeds: Policy, prevention, and control. California Invasive Plant Council Symposium 2003. Kings Beach, CA.
  • Benefield, C. B. (1999). Private and public funding opportunities: Sources of funding for weed management programs. California Exotic Pest Plant Council Symposium '99. Sacramento, CA.
  • Blair M.D., C. E. (2006). Invasive aquatic weeds: Implications for mosquito and vector management activities. Cal-IPC Symposium. Rohnert Park, 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.
  • Connick, S. and M. Gerel (2004). Partnering to prevent invasions of plants of horticultural origin. California Invasive Plant Council Symposium 2004. Ventura, CA.
  • Crosson, H. A. (2004). Water gardening: Pathway to paradise or plant invasion? California Invasive Plant Council Symposium 2004. Ventura, CA.
  • Jackson, N. E. (1996). Control of exotic weeds with Roundup herbicide: A survey of projects around the world. California Exotic Pest Plant Council Symposium. San Diego, CA.
  • Pitcairn, M. J. and D. M. Woods (1998). Control methods: Biological control. California Exotic Pest Plant Council Symposium '98. Ontario, CA.

Other Eichhornia crassipes Information

  • CalPhotos - Images of plants taken mostly in California.
  • Calflora - See the distribution of this species on Calflora's map of California.
  • 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.
  • Bugwood - National database from the Center for Invasive Species and Ecosystem Health at the University of Georgia.