Aquatic Invasive Plant Identification Cards: Eurasian Watermilfoil vs. Northern Watermilfoil
DOWNLOADSeptember 2, 2026 - Jo Latimore, Paige Filice, Erick Elgin, and Chelsea Cooper
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EmailWith its abundance of lakes, rivers, and wetlands, Michigan is vulnerable to the impacts of aquatic invasive plants. Invasive plants can negatively impact habitat, water quality, and biodiversity. Fortunately, new invasions can often be stopped if caught early. To help Michiganders identify invasive aquatic plants, Michigan State University Extension created a series of illustrated identification cards.
Learning to identify aquatic invasive plants is critical to slowing their spread in Michigan lakes, rivers, and wetlands. If your organization is interested in large quantities of any of these identification cards for distribution, they are currently available in packs of 100 of each design at no cost by filling out our request form at bit.ly/aiscards. You may also be interested in our more detailed 2025 publication, “Aquatic Invasive Plants: A Field Guide for Michigan Lakes, Streams, and Ponds.”
Eurasian Watermilfoil vs. Northern Watermilfoil
Eurasian watermilfoil is among the most widespread invasive plants in Michigan’s waters. Unfortunately, it can easily be confused with many of Michigan’s 6 native watermilfoil species that have similar green, feather-like leaves arranged in whorls around the stem. Eurasian watermilfoil is distinguished by having more than 12 pairs of leaflets per leaf, and these leaves fall limp when removed from the water. It also tends to have a reddish-brown stem. A hybrid form may also be encountered, which leads to intermediate traits with native Northern watermilfoil.
