Variable-leaved watermilfoilMyriophyllum heterophyllum
Click here for information at USGS!
Click here for a quick guide for this species. PDF format!Similar Species
- Most native watermilfoil species
History
- Native to the southeast and midwest United States
- First recorded in New England in 1932 in Bridgeport, Connecticut
Characteristics
- Rooted perennial aquatic plant
- Forms dense beds
- Stems are thick (3mm), robust, and frequently, but not always, red
- Submerged leaves finely divided (pinnate), resembling a feather, arranged in whorls of 4 to 6 around the stem
- Emergent floral spike produces long, slender leaves with serrated margins that look nothing like the submerged leaves
- Flowers grow from base of emergent leaves
Habitat
- Slow-moving waters, including lakes and ponds, but occasionally rivers
- Grows in a wide range of temperatures and water conditions, including acidic and calcium-rich lakes
- Water depths to 8 ft (2.4 m), deeper if water clarity is adequate
Known Distribution in the Northeast
- As far north as Maine and Quebec
Impacts
- Can form dense mats that shade and crowd out native aquatic plants
- Thick growth can impair recreational uses of waterways, including boating, swimming, and fishing
- Degrades habitat of fish and other wildlife
- May provide breeding areas for mosquitoes
Variable-leaved watermilfoil
Variable-leaved watermilfoil
Variable-leaved watermilfoil (Myriophyllum heterophyllum)Graves Lovell, Alabama Dept. Conservation and Natural Resources
Variable-leaved watermilfoil
Variable-leaved watermilfoil
Variable-leaved watermilfoil