We’ve compiled a list of the most common Wisconsin aquatic plant species with brief descriptions and treatment options. Many of these descriptions were summarized from Through The Looking Glass, a phenomenal resource providing plant descriptions, pictures, similar species, habitat, and community values. Unlabled pictures are from Wiki Commons and considered open content under the GNU Free Documention License. All labled pictures are property of either Virginia Tech (Weed ID Guide), Paul Skawinski (author of Aquatic Plants of the Upper Midwest), or Lake and Pond Solutions Co. and their use is strictly prohibited without prior written consent.
Please be aware that lake or pond treatments are complex and require proper plant ID, accurate acreage and depth measurements, and sometimes multiple products for proper control. Permits may be required!! Understand that native plants play a vital role in the lake and pond ecosystem and complete removal may have detrimental impacts. Please contact us for further product information or treatment assistance. You may also enter the LPS Store to buy products, browse our product labels or view the glossary of plant terms.
Fruits & seeds: Seeds eject from mature seedpods when touched. Seeds are viable in the soil for 12-18 months.
Roots: Fairly shallow, fleshy roots.
Species Assessment Groups (SAG) were assembled to recommend a legal classification for each species considered for NR 40. The recommendation for policeman’s helmet was based upon this literature review [PDF] developed by the department.
Flowers: Flowers resemble an English policeman’s helmet, giving this plant its common name. Flowers are spurred, five parted and pink to white to purple in color. Flowers arise from the leaf axils.
Leaves & stems: Fleshy, smooth, hollow stems with a reddish color. Stems are multi-branching with distinct swollen nodes. Leaves are large, simple and toothed with a pointed tip. Leaves are arranged opposite or are often whorled in groups of three.
Similar species: Policeman’s helmet could be mistaken for other members of the genus Impatiens. This species pinkish-purple flowers, swollen nodes and serrated leaves distinguish it from two native Wisconsin jewelweed species (Impatiens capensis, Impatiens pallida).