parrotfeather: Myriophyllum aquaticum (Haloragales: Haloragaceae): Invasive Plant Atlas of the United States

parrotfeather	USDA PLANTS Symbol: MYAQ2 U.S. Nativity: Exotic Habit: Aquatic Forbs/Herbs
Myriophyllum aquaticum (Vell.) Verdc.

Jump to: Resources | Images | Distribution Maps | Sources

Taxonomic Rank: Magnoliopsida: Haloragales: Haloragaceae
Synonym(s): parrotfeather watermilfoil, water-feather, Brazilian water-milfoil, parrotfeather
Native Range: Brazil, Argentina, Chile ()
Parrotfeather watermilfoil is an herbaceous, rooted, submerged/emergent plant that invades aquatic habitats throughout much of the United States. Stems are stout and blue-green in color. Leaves are abundant, whorled, pinnately compound, and finely dissected. Submersed leaves are 0.6-1.4 in. (1.5-3.5 cm) long and have 20 to 30 divisions per leaf. Emergent leaves are 0.8-2 in. (2-5 cm) long, less divided and greener than the submersed leaves. As only female plants occur in North America, reproduction occurs vegetatively. Inconspicuous flowers are formed in the axils of the emergent leaves in the spring (sometimes fall). Parrotfeather watermilfoil is found in lakes, ponds, and slow moving streams where it can form dense mats of vegetation. These mats can clog waterways, impede boating traffic, disrupt the growth of native vegetation and provide a breeding ground for mosquitoes. Parrotfeather watermilfoil is native to South America and was first introduced into the United States in the Washington DC area around 1890 as an aquarium and aquatic garden plant.

Identification, Biology, Control and Management Resources

Plant Invaders of Mid-Atlantic Natural Areas - National Park Service and U.S. Fish and Wildlife Service
Invasive Plant Atlas of New England - University of Connecticut
Global Invasive Species Database - Invasive Species Specialist Group

Selected Images from Invasive.org

View All Images at Invasive.org

Control; Control with 2,4-D and wetting agent Utah State University Archive, Utah State University, Bugwood.org Additional Resolutions & Image Usage	Infestation; Alison Fox, University of Florida, Bugwood.org Additional Resolutions & Image Usage	Plant(s); Alison Fox, University of Florida, Bugwood.org Additional Resolutions & Image Usage	Plant(s); Close-up with pennywort in center Alison Fox, University of Florida, Bugwood.org Additional Resolutions & Image Usage
Foliage; Emergent stems Leslie J. Mehrhoff, University of Connecticut, Bugwood.org Additional Resolutions & Image Usage	Plant(s); Nancy Loewenstein, Auburn University, Bugwood.org Additional Resolutions & Image Usage

EDDMapS Distribution:
This map is incomplete and is based only on current site and county level reports made by experts and records obtained from USDA Plants Database. For more information, visit www.eddmaps.org