Common Name: American Waterweed
Species Name: Elodea Canadensis
American waterweed lives entirely underwater with the exception of small white flowers which bloom at the surface and are attached to the plant by delicate stalks. It produces winter buds from the stem tips which overwinter on the lake bottom. It also often overwinters as an evergreen plant in mild climates. In the fall leafy stalks will detach from the parent plant, float away, root, and start new plants. This is American waterweed’s most important method of spreading, with seed production playing a relatively minor role.
Common Name: Coontail/Hornwort
Species Name: Ceratophyllum Demersum
Coontail is also known by the common name hornwort. The common names refer to its full, bottle-brush-like growth form and its forked, antler-shaped leaves. The Latin name Ceratophyllum pertains to the horned leaf edges- Cerato derives from the Greek word “keras” (horn, as in rhinoceros). Phyllum means leaf.
Coontail does not produce roots, instead it absorbs all the nutrients it requires from the surrounding water. If it is growing near the lake bottom, it will form modified leaves which it uses to anchor to the sediment. However, it can float free in the water column, and sometimes forms dense mats just below the surface. Because it gets nutrients from the water, it grows best where these nutrient levels are high. This weed is also shown in the Floating Weeds Section.
Common Name: Variable-Leaf Milfoil
Species Name: Myriophyllum Heterophyllum
Variable-Leaf Milfoil is a BIG problem on our lakes and the primary target of our weed treatment efforts. It is a submersed, perennial usually found rooted in up to 6 feet of water. Dense growths of Variable-Leaf Milfoil provide breeding areas for mosquitoes and degrade water quality and habitat for fish and wildlife. Although the plant is largely submersed, an emergent portion may extend 4 to 6 inches above the surface. Reproduction occurs both vegetatively and by seed production. This is a very common Aquarium plant. NEVER (let’s repeat… NEVER) empty a fish tank where it can drain into the lake!! This will introduce undesirable exotic weeds into the ecosystem of our lakes.
Learn more about Variable-Leaf Milfoil:
Global Invasive Species Database
Invasive Plant Atlas of New England
Common Name: Robbin’s Pondweed
Species Name: Potamogeton Robbinsii
Most specimens of this species are rarely seen in flower and even more rarely in fruit. The plants provide cover for fish.
Common Name: Variable Leaved Pondweed
Species Name: Potamogeton Gramineus
Common Name: Wild Celery
Species Name: Valisneria Americana
The plants grow to 18 inches or more in length and are medium to dark green. They are vigorous growers, reproducing by runners.
Common Name: Slender Naiad
Species Name: Najas Flexilis
A slender, elongated, rooted aquatic plant, seldom found in water less than 3′ deep. Distinguished from similar species by slender, opposite leaves which clasp the stem and elongated, wavy form, rooted to the bottom.
