Photographer: Minnette Marr Affiliation: Lady Bird Johnson Wildflower Center Source: Texasinvasives.org Copyright: CC BY 3.0 US
Aquatic plant with stout stems; both stems and submerged leaves may be reddish tinted; gray-green tips of the stems with leaves may protrude above the water. Leaves are finely divided, pale whitish green in color, in whorls of mostly five with smooth leaf margins. Flowers are in axils of emerged leaves; fruits up to 1/8 inch long.
Parrotfeather milfoil can form dense mats and compete with native aquatic plants, especially in shallow ponds. It also provides habitat for mosquito larvae impedes boats and clogs drainage ditches.
Spreads vegetatively from whole plants or fragments; it can be dispersed by people dumping aquaria into rivers and ponds and by animals carrying fruits and fragments on their bodies.
Parrotfeather milfoil was introduced to the United States in the Washington, DC area about 1890. Commonly sold for aquaria and aquatic gardens, it has escaped to some freshwater ponds in this region.
South America: Brazil, Argentina and Chile
U.S. Habitat: Parrotfeather milfoil is limited to non-tidal fresh waters.
U.S. Present: AL, AR, AZ, CA, CT, FL, GA, HI, ID, KS, KY, LA, MD, MO, MS, MT, NC, NJ, NY, OH, OK, OR, PA, SC, TN, TX, VA, WA
To view a distribution map provided by EDDMapS click here
Resembles several plants including coontail (Ceratophyllum demersum), invasive hydrilla (Hydrilla verticillata), invasive Eurasian watermilfoil (Myriophyllum spicatum), and possibly elodeas.
Attempting control by manual or mechanical means tends to spread the plants and should only be conducted in small, contained water bodies. Draining a pond in the summer achieved control in one instance, but draining may not achieve control in winter. Control with herbicides is difficult because the emergent stems and leaves have a waxy cuticle that repels herbicides. Research into biological control of parrotfeather milfoil is ongoing.
USE PESTICIDES WISELY: Always read the entire pesticide label carefully, follow all mixing and application instructions and wear all recommended personal protective gear and clothing.
Contributions from Texas Invasives for this species page are greatly appreciated.
Cilliers, C.J. 1999. Biological control of parrot's feather, Myriophyllum aquaticum (Vell.) Verdc. (Haloragaceae), in South Africa. African Entomology 113-118.
Kasselman, C. 2011. Myriophyllum aquaticum (Vellozo) Verdcourt var. santacatarinense Kasselman, var. nov. (Haloragaceae). Aqua Planta 36 (4): 128-133.
Swearingen, J., K. Reshetiloff, B. Slattery, and S. Zwicker. 2002. Plant Invaders of Mid-Atlantic Natural Areas. National Park Service and U.S. Fish & Wildlife Service, 82 pp.