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?
CDFA Rating: C?
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 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
- Don’t sell a pest: A new partnership to prevent plant invasions through horticulture. Connick, Sarah; Gerel, Mike. Vol 13, Issue 2
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.
- Optimizing control of parrotfeather (Myriophyllum aquaticum) in Washington with herbicides and environmental constraints. Kuehne, Lauren; Olden, Julian; Adey, Amaryllis; Hicks, Madeleine; Wamsley, Bill; Wilson, Timothy; Cracknell, Paula; Murphy, Mike; Brownlee, Todd (2022)
- The safe and effective application of aquatic herbicides. Hoffmann, Krista (2020)
- Partnering to prevent invasions of plants of horticultural origin. Connick, Sarah; Gerel, Mike (2004)
- Aquatic weeds: Policy, prevention, and control. Anderson, Lars (2003)
Other Myriophyllum aquaticum Information
- 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.