Myriophyllum aquaticum

Myriophyllum_aquaticum_By André Karwath
Photo by André Karwath, via Wikimedia Commons

Synonyms: Enhydria aquatica, Myriophyllum brasiliense, M. proserpinacoides

Common names: parrotfeather; Brazilian watermilfoil; parrotfeather watermilfoil; thread-of-life;

Myriophyllum aquaticum (parrotfeather) is a stout aquatic perennial (family Haloragaceae) that forms dense mats of intertwined brownish stems (rhizomes) in water. Myriophyllum aquaticum can be found in freshwater lakes, ponds, and canals with slow-moving waters in northern and central California. This invasive plant may compete with native aquatic plants, eliminating them or reducing their numbers in infested sites. It forms dense mats that can entirely cover the surface of the water in shallow lakes and other waterways. The species does not produce viable seed and its distribution is limited to vegetative dispersal mechanisms.

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

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 Myriophyllum aquaticum 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.