Aquatic Plant Identification

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Aquatic plant identification is a critical component to understand your plant community and the appropriate way to initiate management.  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. Unlabeled pictures are from Wiki Commons and considered open content under the GNU Free Documentation License while all labeled 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 LLC 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!! 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.

TYPICAL TREATMENT: Aquastrike, Navigate or Reward
NATIVE: Common bladderwort will usually be found free floating as it has no visible roots. It has floating stems with leaf-like branches that fork 3-7 times. Scattered on these branches are bladders that trap young prey. Young bladders are transparent and green tinted, but they become dark brown to black as they age. Common bladderwort will also produce yellow flowers that protrude above the water surface.
Bladderwort
TYPICAL TREATMENT: Aquastrike, Aquathol or Reward
NATIVE: Bushy pondweed has fine branched stems that emerge from a thin rootstalk. Leaves are narrow with a broad base where they attach to the stem. Edges of the leaf will be finely serrated. Tiny flowers and seeds can develop in the leaf axils.
Bushy Pondweed (naiad)
TYPICAL TREATMENT: Clipper, Captain XTR, Reward or SeClear G
NATIVE: This unusual type of algae resembles a higher plant without true roots. Main branches are often encrusted by calcium carbonate, giving it a harsh, crusty feel. Chara is typically low growing and can be identified by its musky odor.
Chara (Muskgrass)
TYPICAL TREATMENT: Aquastrike, Aquathol or Reward
NATIVE: Clasping-leaf pondweed has oval to somewhat lance-shaped leaves that ``clasp`` around one-half to three-quarters of the stem circumference. Leaves have 13-21 veins and white fibers are typically found at the leaf node. No floating leaves are produced. Fruiting stalks develop with cylindrical spikes that are packed with seeds. Each seed is plump and round with a prominant beak.
Clasping-leaf Pondweed
TYPICAL TREATMENT: Aquastrike, Avast/Sonar or Reward
NATIVE: Coontail has long, trailing stems that lack true roots though the plant may be loosely anchored. Leaves are stiff and arranged in whorls of 5-12. Each leaf is forked once or twice and the leaf divisions have teeth along the margins that are tipped with a small spine. Leaves are usually more closely spaced near the ends of branches, creating the raccoon tail appearance.
Coontail
TYPICAL TREATMENT: Aquathol
EXOTIC: Curly-leaf has leaves that are oblong and are attached directly to the stem in an alternating pattern. Margins of the leaves are wavy, finely serrated, and typically resemble lasagna noodles. Curly-leaf produces small pinecone like seeds called turions that can lay dormant in a water body for 5-7 years making it very hard to eradicate.
Curly-leaf Pondweed
TYPICAL TREATMENT: Clipper or Sonar/Avast!
NATIVE: Duckweed has round to oval-shaped leaf bodies called fronds that float individually or in groups on the water surface. Each frond has three faint nerves, one root and no stems. Duckweed is usually found in ponds protected from the wind where wave action in minimal.
Duckweed
TYPICAL TREATMENT: Aquastrike or Reward
NATIVE: Elodea has slender stems that emerge from a shallow rootstalk. The small lance-shaped leaves attach directly to the stem. Leaves are in whorls of three, or occasionally only two and tend to be more crowded toward the stem tips. Elodea typically stays low growing to the bottom but can become problematic in shallow waters.
Elodea (Common Waterweed)
TYPICAL TREATMENT: Avast/Sonar, ProcellaCOR, WEEDestroy AM-40
EXOTIC: EWM has long spaghetti-like stems sometimes 2 or more meters in length. Leaves are divided like a feather with 14-20 pairs of leaflets. Leaves are in whorls of 4-5 and can be widely spaced. EWM can reproduce from fruiting bodies and from fragmentation making it hard to control once established.
Eurasian Water-milfoil (EWM)
TYPICAL TREATMENT: Aquastrike, Aquathol or Reward
NATIVE: The stems are strongly flattened and have an angled appearance. Stiff linear leaves have a prominent midvein and many fine, parallel veins. Flat-stem does not have any floating leaves except for its nutlike fruits that are arranged in a cylindrical spike that pokes out of the water.
Flat-stem Pondweed
TYPICAL TREATMENT: Aquastrike, Aquathol or Reward
NATIVE: Floating-leaf pondweed has stems that emerge from red-spotted rhizomes. Submersed leaves are stalk-like, with no obvious leaf blade. Floating leaves are heart-shaped at their base. The point where the floating leaf attaches to the stalk is distinctive. It looks like someone pinched the stalk and bent it, so the leaf blade is at a right angle to the stalk and lays flat on the water. Flowers and fruit are produced in a dense cylindrical spike that pokes above the water surface. Fruit is oval to egg-shaped and plump with a wrinkled appearance on the sides and a short beak.
Floating-leaf Pondweed
TYPICAL TREATMENT: Clipper or Sonar/Avast!
NATIVE: Forked Duckweed has a simple, flattened leaf body or frond that is long stalked with three faint nerves and a single root. Lateral fronds often remain attached to the parent frond, creating a ``rowboat and oars`` shape. Flowers are seldom produced and can only be seen with magnification. Forked Duckweed is often found just under the water surface, seldom making it a nuisance.
Forked Duckweed
TYPICAL TREATMENT: Clearcast or Habitat with AquaNeat or Shore-Klear
EXOTIC: Phragmites have stems 2-4 meters tall that grow out of stout rhizomes. Some of the stems are topped with spreading clusters of spikelets. Each spikelet has 3-7 florets and long silky hairs that give a feather duster appearance. It grows along shorelines and in a variety of wetlands.
Giant Reed (Phragmites)
TYPICAL TREATMENT: Aquastrike, Aquathol or Reward
NATIVE: Horned Pondweed has long, linear, thread-like leaves that are mostly opposite or arranged in whorls on slender branching stems. Leaf tips gradually taper to a point, and a thin sheath or stipule covers the basal parts of leaves. Horned pondweed gets its name from it's seeds that occur in groups of 2-4 and are horned shaped.
Horned Pondweed
TYPICAL TREATMENT: Contact LPS biologist
EXOTIC: Hydrilla has a long stem that is branched with oppositely arranged leaves at the bottom. It has whorls of three to eight leaves with the leaf having an oval shape with toothed margins. Hydrilla can reproduce from fragmentation making it hard to control once established. Hydrilla has been rarely found in Wisconsin and should be reported to the DNR if seen.
Hydrilla
TYPICAL TREATMENT: Aquastrike, Aquathol or Reward
NATIVE: Illinois Pondweed has stout stems that emerge from a thick rhizome. Most of the submerged leaves are lanced shaped to oval and either attached directly to the stem or have a short stalk. The leaves have 9-19 veins and often have a sharp needle like tip. The stipules are free in the axils of the leaves and have two prominent ridges called keels.
Illinois Pondweed
TYPICAL TREATMENT: Aquastrike, Aquathol or Reward
NATIVE: Large-leaf Pondweed has the broadest leaf (3.5-7 cm wide) of any pondweed in our region. These leaves are arched and slightly folded. The leaf varies in length and is lined with many veins (25-37). Large-leaf Pondweed has larger leaves than Illinois Pondweed and has more veins throughout the leaf.
Large-leaf Pondweed
TYPICAL TREATMENT: Aquastrike, Aquathol or Reward
NATIVE: Leafy pondweed has freely branched stems that emerge from slender rhizomes. The narrow, submersed leaves have parallel sides that narrow slightly where they attach to the stem. The tip of the leaf usually tapers to a point. No floating leaves are produced. Flowers and fruit are produced on short stalks in the axils of the upper leaves. Fruits are in tight clusters and are flattened with a wavy ridge and a short beak.
Leafy Pondweed
TYPICAL TREATMENT: Aquastrike, Aquathol or Reward
NATIVE: Long-leaf pondweed has stems that emerge from branching rhizomes. Submersed leaves are narrowly lance-shaped and gradually taper to a long leaf stalk. The floating leaves also taper to long leaf stalks. Flowers and fruit are produced on a dense cylindrical spike that pokes up above the water surface. The long leaf stalks of the submersed leaves help separate long-leaf pondweed from specides with similiar floating leaves.
Long-Leaf Pondweed
TYPICAL TREATMENT: Captain XTR, Clipper, Cutrine Granular or SeClear G
NATIVE: Nitella is a type of algae that looks like a higher plant but with no true roots. Branches are arranged in whorls around the stem, but unlike chara, are smooth and translucent green. Nitella also lacks the skunky smell of chara.
Nitella (Stonewort)
TYPICAL TREATMENT: Avast/Sonar, ProcellaCOR or WEEDestroy AM-40
NATIVE: NWM has stems that are sparingly branched and fairly erect in the water. The leaves are divided like a feather and have 5-12 pairs of thread-like leaflets. The lower leaflet pairs are longer than the upper ones, creating a Christmas tree shape. The leaves are arranged in whorls with 4-5 leaves per whorl.
Northern Water-Milfoil
TYPICAL TREATMENT: Aquathol, Navigate, or Reward
EXOTIC: Parrot Feather has long unbranched stems emerging from roots and rhizomes. These stems can grow to a height of 6`` above the water surface. Slender, feather-like leaves occur in whorls of 4 to 6 leaves. Whorls are openly spaced toward the base, and more closely arranged toward the growing tip. Each leaf will have 10 - 18 leaflet pairs. Emmergent leaves are robust, vibrant green, and covered with a waxy coating. Small white flowers can be found on femail plants in the axils of emmergent leaves. Report any infestations to the DNR.
Parrot Feather
TYPICAL TREATMENT: Contact LPS Biologist
EXOTIC: Pennywort is a small perennial plant typically found along streams or rivers in small but dense colonies. The stems are slender and tend to creep over moist or wet ground, rooting at the nodes. The leaf is attached at the base and typically is found with 6-10 shallow lobes around the margin. The flowers are whitish or greenish but are so small they are rarely noticed.
Pennywort
TYPICAL TREATMENT: Aquaneat or Shore-Klear
EXOTIC: Purple Loosestrife has angled stems that emerge from a woody rootstalk. Leaves are lance shaped, attached directly to the stem, and often have fine hairs on the surface. Clusters of magenta flowers are produced in leaf axils of a terminal spike. Each flower has 5-7 narrow petals that are wrinkled with a tissue paper consistency. It is typically found in moist soils and shallow water.
Purple Loosestrife
TYPICAL TREATMENT: Contact LPS biologist
EXOTIC: Sacred Lotus produces individual leaves and flowers directly from the root system with thick rhizomes. The blades of the leaves either float on the surface of the water or are held up to 6' above the water by their petioles. Leaf margins are smooth and undulate up and down. Individual flowers are also held above the water and consist of about 15 pink petals, a golden receptacle, and dense ring of golden stamens. Flowers are eventually replaced by a seed pod that becomes dark brown and bends downward to release seeds into the water. Sacred Lotus spreads by its rhizomes or seeds which have been documented to remain viable for over 1200 years!
Sacred Lotus
TYPICAL TREATMENT: Aquastrike, Aquathol or Reward
NATIVE: The stems of Sago Pondweed sprout from slender rhizomes that are peppered with starchy tubers. The leaves are very thin and resemble pine needles, ending in a sharp point. Each branch may be forked several times into a spreading, fan-like arrangement. Flowers and fruits are produced on a slender stalk that may be submersed or floating on the water surface.
Sago Pondweed
TYPICAL TREATMENT: Aquastrike, Aquathol or Reward
NATIVE: Small pondweed has slender stems that emerge from a slight rhizome and branch repeatedly near the ends. Submersed leaves are linear and attach directly to the stem. The leaves have three veins and the mid-vein may be bordered by several rows of hollow cells. No floating leaves are produced. The flowers and fruits are produced in 1-4 whorls on a slender stalk. The oval fruit is rather plump and has a smooth back and short beak.
Small Pondweed
TYPICAL TREATMENT: Aquaneat, Navigate, Navitrol or Renovate
NATIVE: Spatterdock has a sturdy leaf stalk that has a flattened upper surface with a narrow wing running down each side. Leaves of spatterdock are heart shaped with rounded lobes that are parallel or overlapping. Flowers are globular to saucer shaped with 5-6 yellow sepals that often have a deep red patch at the base.
Spatterdock
TYPICAL TREATMENT: Aquastrike, Aquathol or Reward
NATURALIZED EXOTIC: Spiny naiad is a submersed plant similar to Bushy Pondweed but has larger leaves that are coarsely toothed. The backs of the leaves also have spines along the midrib. The reddish-brown seeds are oval in shape with an irregularly pitted surface. The seeds can be found singularly situated in the leaf axils.
Spiny Naiad
TYPICAL TREATMENT: Aquastrike, Aquathol or Reward
NATIVE: Variable-leaf pondweed has both floating and submerged leaves that are elliptical to oval in shape. Floating leaves usually have 7-10 distinct veins. Submersed leaves are arranged alternately on the stem and are usually smaller than the floating leaves. A fruiting spike will occur on a short stalk and emerge just above the water surface.
Variable-leaf Pondweed
TYPICAL TREATMENT: Aquastrike or Reward
NATIVE: There are two white-flowered and one yellow flowered water buttercup species common in our region. Water buttercup has long, branched stems that emerge from both trailing runners and buried rhizomes. The leaves are finely cut into thread-like divisions (white) or flattened divisions (yellow) and either attach directly to the stem or have a very short leaf stalk. Leaves emerge along the stem in an alternate arrangement and are usually stiff enough to hold their shape when lifted out of the water. White or yellow, five-petaled flowers are produced on stalks just above the water surface. As flowers develop into fruit, the stalks curve back into the water and a cluster of 15-25 nutlets is produced.
Water Buttercup (Water Crowfoot)
TYPICAL TREATMENT: Contact LPS Biologist
EXOTIC: Water Hyacinth has leaves that are large and broadly lance-like extending from an inflated stalk. Flowers are blue, violet, or white. The roots are dark and fibrous. The height of the plant ranges from a few inches to three feet tall. Water Hyacinth can reproduce from seeds or by fragmentation making it difficult to control. If found in a water body it should be reported to the DNR.
Water Hyacinth
TYPICAL TREATMENT: Clipper
NATIVE: Watermeal is composed of pale green, asymmetrical globes with no roots, stems, or true leaves. Watermeal has the distinction of being one of the world's smallest flowering plants, however the flowers can only be seen under magnification and are seldom present. It typically grows in areas that are not disturbed by wind and wave action.
Watermeal
TYPICAL TREATMENT: Aquastrike, Aquathol or Reward
NATIVE: Water Stargrass has slender, freely branched stems that emerge from a buried rhizome. The narrow, alternate leaves attach directly to the stem with no leaf stalk and lack a prominent midvein. Yellow, star-shaped flowers are produced individually in addition to a capsular fruit that contains 7-30 seeds.
Water Stargrass
TYPICAL TREATMENT: Aquastrike, Aquathol or Reward
NATIVE: White-stem Pondweed has a zig-zag stem that emerges from a stout, rust-spotted rhizome. Submersed leaves are lance to oval-shaped and wrap around one-third to one-half the stem's diameter. The leaves have 3-5 stong veins and many weaker ones along with a tip that is boat-shaped. Another tell tale sign of this species are the white and fibrous stipules in the leaf axils. Flowers and fruits are arranged in a cylindrical spike that may be continuous or interrupted. Fruit is oval to egg-shaped and rather plump with a short beak and sharp ridge.
White-stem Pondweed
TYPICAL TREATMENT: Aquaneat, Navigate, Navitrol or Renovate
NATIVE: White water lily has a cylindrical leaf attached to a round stalk. The flowers float on the waters surface and are borne on individual flower stalks that rise directly from the rhizome. They have four greenish sepals and numerous white petals in a circular arrangement.
White Water Lily
TYPICAL TREATMENT: ProcellaCOR
NATIVE: Whorled water-milfoil has greenish brown stems. The leaves are in whorls of 4-6 with 7-10 threadlike paired leaflets. They are long, limp, and have a feather-like appearance. Flowers and fruits are formed in the axils of whorled bracts that typically stand erect above the surface of the water. Later in the growing season, club shaped winter buds comprised of small stiff leaves will form.
Whorled Water-milfoil
TYPICAL TREATMENT: Aquastrike or Reward
NATIVE: The trailing stems of wigeon grass emerge from a shallow root system. Stiff, slender leaves are scattered on the stems. Each leaf has an expanded open sheath at the base. The flower stalk is long and spirally twisted. As the flowers mature, the fruit is elevated on stalks in an umbrella-like cluster.
Wigeon Grass
TYPICAL TREATMENT: Contact LPS biologist
NATIVE: Wild Celery has ribbon-like leaves that emerge in clusters along a creeping rhizome. The leaves have a prominant central stripe and cellophane-like consistency. The leaves are mostly submersed, with just the tips trailing on the surface of the water. Male and female flowers are produced on separate plants though they are very small (1 - 6.5 mm wide).
Wild Celery (Eel-Grass)
TYPICAL TREATMENT: ProcellaCOR
EXOTIC: If Yellow Floating Heart is found in your water body please contact the DNR. Just recently found in Wisconsin, Yellow Floating Heart can be very hard to eradicate once established. Identified by its ``heart-like`` shape, yellow flowers, and wavy purple edges, it is smaller than spatterdock rarely reaching sizes larger than your hand.
Yellow Floating Heart

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