Maine Lakefront Property Owners: Learn To Recognize Invasive Aquatic Plants 101

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Maine Lakefront Property Owners: Learn To Recognize Invasive Aquatic Plants 101

Maine Lakefront Property Owners: Learn To Recognize Invasive Aquatic Plants 101

Lakefront Property Owners Keep Eyes Out For Invasive Plants Such As European Frog-Bit

by Leigh Macmillen Hayes
In Maine, we know that plant life in lakes is important for good fisheries. Aquatic plants provide cover and foraging opportunities.

 

 

 

 

 


With invasive aquatic plants, however, just the opposite occurs. High invasive plant density crowds out native plants, stunts the growth of some fish species and reduces their movement. According to the Maine Volunteer Lake Monitoring Program, it can also shade the bottom, reduce the number of snails and other animals, and change water chemistry.
As lakefront property owners, it affects us in other ways as well. How many times have you had to deal with weeds entangled in your engine motor? And what about the value of your lakefront property if the lake is infested? How does this affect tourism in our state?
There are eleven known invasive aquatics plants in Maine. We thought we’d give you a primer and break them up into categories featured in a few blogs. Let’s begin with the floating-leaf plant community.
Floating-leaved plants have waxy leaves that float on the surface. There are native plants with floating leaves such as the following: fragrant water lilies, watershield, spatterdock and little floating heart. Those are the good guys.
And then there are the three invasives found in this community: European frog-bit, yellow floating heart and water chestnut.
European frog-bit thrives in open marshes and quiet backwaters. This is a free floating plant — not attached by the stem to the sediment below. Instead, it forms dense floating colonies.
The leaf is heart- or kidney-shaped. The vein pattern is concentric, meaning it follows the pattern of the leaf. Below the leaves are elongated stalks that occur in clumps. These form a bouquet-like rosette, connected with a runner, much like a strawberry plant. The flower has three white petals and a yellow center. This invasive plant may be confused with all four of the native floating-leaved plants.

 

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Yellow-floating heart

Yellow-floating heart grows in various substrates including sand, mud and gravel along the water’s edge to about 13 feet of water, aka the littoral zone.
The leaf is rounded to heart-shaped. Long stalks extend from the rooted stems to the leaf. Loosely branched groups of several leaves are supported by each rooted stem. (Note: all heart-shaped floating-leaved plants native to Maine produce only one leaf per rooted stem.) Look for the wavy, almost scalloped outer edges and purplish undersides of the leaves. One to five bright yellow flowers with five distinctly fringed petals, are held above the surface on a slender stalk.
This aquatic perennial propagates by seeds, fragmentation and spreading rhizomes. Most floating-leaved plants lack the ability to propagate by fragmentation. This plant does so, however, as broken leaves with attached stem parts will form new plants. Therefore, don’t rake it or chop it with your boat’s motor. (Actually, don’t use your rake or boat to clear the plants. First, you shouldn’t be clearing the plants to begin with and second, using a motor boat or jet ski to clean your swimming area may mean that you are causing more plants to grow rather than less if they propagate by fragmentation. Hand pulling is a much better approach. Plus, your neighbors may not appreciate the huge wad of plants that then float over to their dock or beach.)
The Yellow Floating Heart may be confused with European frog-bit, fragrant water lily, little floating heart, spatterdock and watershield.

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Water Chestnut

Our third floating invasive is the water chestnut. This one prefers the soft sediments of nutrient-rich waters in lakes. It’s well adapted to life at the shoreline, muddy or not.
Water chestnut is a bit easier to identify because it has two distinct leaf types. Look for a triangular or fan-shaped leaf with obvious teeth along the margins. While the upper surface is glossy, you’ll see that the undersides are covered with soft hairs. The leaves radiate and are joined to the submersed stem by petioles or short stems. The petioles have spongy bladders that provide buoyancy. The other leaf type is the rosette that begins as linear and divided, but becomes feather-like.
Small white flowers occur above the rosettes in mid-summer. Each emerges on its own stalk, coming from the axil of the floating leaves. The woody, nut-like fruits have four sharp barbs, making this one easy to identify later in the season. This plant is not confused with any of the others.
To learn more about lakefront property for sale  on Mousam Lake, click on the green box above.
To learn more about the Shapleigh and Acton area, click on the blog links below.
Mousam Lake in Southern Maine – Perfect for Boaters, Anglers and Vacationers
Hikes near Mousam Lake in Shapleigh and Acton, Maine
Lakeside Sport & Marine On Mousam Lake, Shapleigh, Maine Meets Your Boating Needs

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