Myriophyllum aquaticum

Parrot feather

Nonnative to Florida Invasive

Species Overview

Native to: South America

Parrot feather was introduced to the United States in the Washington DC area around 1890. Commonly sold for aquaria and aquatic gardens, it has escaped cultivation and become invasive in ponds and other calm waterbodies across the country. It has been vouchered in Florida as early as the 1930s.

Species Characteristics

Family: Haloragaceae

Habit: Perennial aquatic plant

Leaves: Oblong, deeply cut and have a filiform, feathery appearance, arranged in whorls of 4-6 about the stem. Aerial foliage has a deeper blue-green color, submerged foliage is bright green.

Flowers: Inconspicuous flowers are formed in the axils of the emergent leaves.

Fruit/Seeds: No fruit is produced in the United States as only female plants are known to be present.

Distribution in Florida: Throughout

Impacts

Spreads vegetatively via stem fragments. It can form dense mats outcompeting native plants and reducing biodiversity. It also provides habitat for mosquito larvae, impedes recreational activities and clogs drainage ditches.

Control Methods

Preventive Measures

Clean all boat equipment and gear before leaving infested aquatic areas. 

Cultural/Physical

Water drawdowns may help reduce populations, especially if also subjected to a hard freeze.

Mechanical

Repeated harvesting may help reduce densities but escaped stem fragments will repopulate the area.

Biological

Grass carp may feed on it, but it is not a preferred food and they are more likely to consume other submersed vegetation if present. A few insects (Listronotus marginicollis and Lysathia spp.) have been released in South Africa but not in the U.S.

Chemical

Detailed chemical control recommendations can be found in the Weed Report from Weed Control in Natural Areas in the Western United States. Consult your local UF IFAS Extension Office for management recommendations.

Learn more about this species

Biology and Control of Aquatic Plants Chapter 2.3

UF IFAS Assessment of Non-Native Plants in Florida’s Natural Areas

Atlas of Florida Plants

EDDMapS

USGS NAS

USDA Plant Database

Invasive Species Compendium

CAL-IPC Plant Profile

North Carolina Extension Plant Profile