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Brazilian Water-Milfoil

Myriophyllum aquaticum (my-ree-oh-FIL-um a-KWA-ti-kum)

Family: Haloragaceae Unknown Herbaceous (3-15 ft)

Parrot feather is an invasive water plant that can cover the entire surface of a pond. This plant is native to South America, Australia and New Zealand in the more tropical areas. In the USA it is found in coastal and southern states invading shallow lakes, ponds, ditches and backwaters in rivers forming dense mats. The monocultures disrupt the growth of native aquatic plants and provide breeding areas for mosquitoes as well as impeding water sports. The delicate, feathery bright-green to blue-green leaves grow in a whorl around the stem both in and out of the water. The vines can grow up to 6 feet long and will become erect and leafy at the ends and can root in the soil on the banks of ponds. Only female plants are known to grow in the US so the tiny flowers do not produce fruits. Spread in vegetatively. It is sometimes used in aquariums as an oxygenator. Insects, Diseases, and Other Plant Problems: Listed as invasive by the NC Invasive Plant Council and in other states. See native alternatives to the left.

Source: NC State Extension Gardener Plant Toolbox ↗ NC State Extension Gardener Plant Toolbox, 44 attributes.

How it fits the guild

Guild layer 4 - Herbaceous (3-15 ft)
See companions & conflicts ↓

Companions & Conflicts

Curated pairwise relationships between this plant and others in the library — who feeds whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.

No curated interactions recorded for this species yet.

Also noted by NC State

Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.

Often confused with Myriophyllum spicatum
Similar, less problematic Iris versicolor

Full plant profile

Growing Conditions
Plant type
Perennial; Water Plant
Life cycle
Perennial
USDA zones
6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b, 10a, 10b
Light
Full sun (6 or more hours of direct sunlight a day) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil texture
High Organic Matter
Soil drainage
Frequent Standing Water
NC region
Coastal; Mountains; Piedmont
Mature size
Height: 5 ft. 0 in. - 6 ft. 0 in. | Width: 5 ft. 0 in. - 6 ft. 0 in.
Growth rate
Rapid
Maintenance
High
Canopy layer
4 - Herbaceous (3-15 ft)
Form & Appearance
Habit / form
Creeping; Horizontal; Spreading
Leaf color
Blue; Green
Leaf type
Compound (Pinnately , Bipinnately, Palmately)
Leaf arrangement
Whorled
Leaf shape
Linear
Leaf margin
Entire
Leaf size
< 1 inch long, < 1 inch wide
Hairs present
No
Leaf detail
Small leaves in whorls; on 5-6 foot stems. Aerial foliage has a deeper blue-green color, submerged foliage is bright green.
Flower color
Gold/Yellow; Green
Flower form
Insignificant
Flower size
< 1 inch
Flower detail
Inconspicuous flowers are formed in the axils of the emergent leaves in the spring, Flowers are not pollinated in the US
Bloom time
Spring
Fruit detail
No fruit is produced in the USA as only female plants are known to grow here
Stem color
Green; Red/Burgundy
Stem detail
Dense, tough reddish-green stems
Wildlife & Ecology
Native status
Unknown
Origin
South America, Australia and New Zealand,
Wildlife value
Submerged foliage serves as shelter for fish, helps remove excess nutrients and acts as an oxygenator
Landscape Use
Garden tags
#invasive #full sun tolerant #high maintenance #aggressive #spreading #aquariums #perennial #wet soils tolerant #weedy #pond #wetland
Problems & Resistance
Problems
Invasive Species
Propagation
Division

Planted at Hunnicutt

Nobody’s planted this one yet.