Know your lake plants — get out on your lake and sample!

Bindu Bhakta<bhaktabi@msu.edu>, Michigan State University Extension - September 20, 2012

One key to managing your lake is making accurate identifications of aquatic plants.

Do you know what kinds of plants are in your lake? Being able to accurately identify aquatic plants will help in the management of your lake. Aquatic plants generally fall into one of four categories: plants that float free on the water and are not attached to the lake bottom in any way (“free-floating); plants sticking out of the water (“emergent”); plants with leaves that float on the surface of the water (“floating-leaved”);and those that grow mostly below the surface of the water (“submergent.”)

At first glance, many aquatic plants appear to be very similar and this can be overwhelming. Dividing plants into various categories will help you get started.

Plants that float on or grow above the water’s surface:

Free-floating plants. Examples: duckweed, watermeal
Emergent plants with leaves that extend above the water. Examples: bulrush, cattail
Floating-leaved plants. Examples: water shield, water lily

Plants growing entirely below the surface of the water (“submergent”):

Plants with thread- or needle-like leaves. Examples: coontail, bushy pondweed
Plants with long, ribbon-like leaves. Examples: wild celery, water star-grass
Plants with complex and finely divided leaves. Examples: water milfoil, bladderwort
Plants with oval, oblong or lanceolate leaves. Examples: American pondweed, waterweed

For individuals looking for hands-on guidance while investigating their lake and determining what’s in the water, Michigan State University (MSU) Extension and Oakland County Parks are hosting a hands-on workshop in which participants will have the opportunity not only to learn about inland lake ecology and management, but be actively engaged in the collection of water quality data by measuring various physical and chemical attributes of the water and aquatic plants. The morning session, held inside, will focus on an introduction to lake ecology, aquatic plants and their control, aquatic micro- and macro-organisms and invasive species.

After lunch, which is included in the program, participants will hop aboard a pontoon boat on beautiful Crooked Lake to engage in various water sampling activities as well as collect and identify plants and other biota along the shoreline and adjacent wetland area. Participants will reconvene indoors for a wrap-up session to analyze and review the samples they collected, and ask any additional questions.

This program will be held at Independence Oaks County Park’s Wint Nature Center in Clarkston and will be led by Lois Wolfson, PhD., and Howard Wandell. Wolfson is an aquatic ecologist in both the Department of Fisheries and Wildlife and the Institute of Water Research at Michigan State University. She also serves as the MSU Extension state water quality co-coordinator. Wandell serves as the executive director of the Michigan chapter of the North American Lake Management Society.

This is a rain or shine event, so please dress for the weather. To maximize learning, participants should plan to actively participate in the outdoor workshop activities and are encouraged to bring waders or boots (knee- or hip-high) if possible. Space is limited to 20 participants. Registration deadline is Wednesday, October 3, 2012.

For complete program and registration details, please visit:

Several sources of information are also available to help you identify plants and therefore help manage your lake:

The “Citizen’s Guide for the Identification, Mapping and Management of the Common Rooted Aquatic Plants of Michigan Lakes” is a great resource to help you identify your aquatic plants. It is available for sale from the MSU Extension Bookstore.
Michigan Clean Water Corps (MiCorps). The Cooperative Lakes Monitoring Program (CLMP) provides sampling methods, training workshops, technical support, quality control, and laboratory assistance for volunteers to monitor their lakes. CLMP offers assistance to volunteers to assess plants in their lake. The MiCorps Factsheet, “Aquatic Plant Identification and Management,”provides more details.
Do you suspect you have some invasive species? The Michigan Natural Features Inventory has several guidebooks available to help identify aquatic invasive species.
Michigan Department of Environmental Quality (MDEQ) has a list of great resources, including aquatic plant identification and management guide.
"Through the Looking Glass: A Field Guide to Aquatic Plants"

This article was published by Michigan State University Extension. For more information, visit https://extension.msu.edu. To have a digest of information delivered straight to your email inbox, visit https://extension.msu.edu/newsletters. To contact an expert in your area, visit https://extension.msu.edu/experts, or call 888-MSUE4MI (888-678-3464).