Myriophyllum aquaticum (Vell.) Verdc.


Myriophyllum aquaticum is an herbaceous, rooted, submerged to 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).
No fertile fruit is known to be produced in the United States.
Ecological Threat
Myriophyllum aquaticum's potential range is yet to be determined. In more southern regions, this plant forms monocultures that clog waterways, impeding recreational and commercial boating activities. These monocultures also disrupt the growth of native aquatic plants and provide breeding areas for mosquitoes. Myriophyllum aquaticum is a common water garden plant, which has the potential to escape into local waterways. Control of this plant is extremely costly.


Selected Images


EDDMapS Distribution

EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit

State Regulated List

State Regulated List - This map identifies those states that list this species on their regulated list. For more information, visit

State Regulated List
   No Data for this state
   Troublesome or Common weed in one or more crops

Most Troublesome / Most Common Agricultural Weed List
This map identifies those states that consider this species either most troublesome or most common in at least one commodity. For more information, visit the MTMC project page.

Taxonomic Rank

Kingdom: Plantae
Phylum: Magnoliophyta
Class: Magnoliopsida
Subclass: Rosidae
Order: Haloragales
Family: Haloragaceae
Genus: Myriophyllum
Subject: Myriophyllum aquaticum (Vell.) Verdc.

Synonyms and Other Names

Other Common Names:
parrotfeather watermilfoil, water-feather, Brazilian water-milfoil, parrotfeather

Related Scientific Names:
Enydria aquatica (Vell.) Verdc. (Synonym)
Myriophyllum brasiliense (Vell.) Verdc. (Synonym)
Myriophyllum proserpinacoides (Vell.) Verdc. (Synonym)


Plants - Aquatic Plants