PARROT FEATHER
Myriophyllum aquaticum
NOT NATIVE TO MAINE - INVASIVE
NOTE: All leafy milfoils display a wide range of vegetative variability. Any milfoil found in Maine waters should be considered “suspicious” until a positive identification has been confirmed by someone with the appropriate expertise.
parrot feather in-situ
Habitat: Parrot feather is found in both the emergent and the submersed plant communities of freshwater lakes, ponds, and slow moving streams. It is also adapted to waters with some salt intrusion. While it grows best when rooted in shallow water, it has been known to occur as a floating plant in the deep water of nutrient-enriched lakes. It is well adapted to life at the water’s edge and can survive when stranded on dewatered river banks and lake shores.
Tiny white flowers occur in the axils of
the emergent stems
Description: Long unbranched stems arise from roots and rhizomes. Unburied rhizomes function as a support structure for adventitious roots, and provide buoyancy for emergent growth. Emergent stems may grow to a height of 30 cm above the water surface. Slender, feather-divided leaves occur along the trailing stems in whorls of 4 to 6 leaves. Whorls are openly spaced toward the base, and more closely arranged toward the growing tip. Leaves are 2.5 to 5 cm long, with 10 to 18 leaflet pairs, flattened midribs and a short petiole. The emergent leaves are robust, vibrant green, and covered with a waxy coating. Submersed leaves, in contrast, are limp and brownish, and often in a state of deterioration. Small white flowers (female only) are inconspicuous, and borne in the axils of the emergent leaves.
U.S. range map of parrot feather
Origin and U.S. Range: Parrot feather is native to South America, and is considered invasive in the United States. Nearby populations occur in New York and Rhode Island. Parrot feather is not known to be present in Maine waters.
Thick growth creates the danger of entanglement
Annual Cycle: Parrot feather is an aquatic perennial that propagates through root division and plant fragments. Plants usually flower in the spring but fall flowering also occurs. Male and female flower parts occur on separate plants, and male plants are only known to occur in the plant’s native range. As a result, parrot feather populations in the United States do not produce seeds. Plants die back to their rhizomes toward the end of the growing season. New shoots begin to grow rapidly from overwintering rhizomes as water temperatures rise in the spring.
Look Alikes: When emergent stems and leaves are not present, parrot feather may be confused with bladderworts, hornworts, mermaid weeds, water crowfoots, and other leafy water-milfoils.
Print out a copy for the field
(Adobe Acrobat file) - To get the free Acrobat Reader go to Adobe.com.
Click Images for Larger Version
|
 Water Quality Monitoring |  Aquatic Invasive Monitoring |
Maine Volunteer Lake Monitoring Program
vlmp@mainevlmp.org
24 Maple Hill Road, Auburn, ME 04210
(207)-783-7733
www.MaineVolunteerLakeMonitors.org
© 2009 Maine Volunteer Lake Monitoring Program | website comments to: vlmp@mainevlmp.org
