Submersed Weeds

American pondweed has oval-shaped leaves that spread across the water surface. The seed head extends above the water on slender stalks. American pondweed can form dense mats and block sunlight for submersed vegetation. American pondweed can be mistaken for Illinois pondweed.

Bladderworts are submersed free-floating plants. There are about 200 species in the world, ranging in size from a few inches to several feet long. Tiny bladders attached to the leaves trap and digest very tiny animals. Utricularia species occurs almost always (estimated probability 99%) under natural conditions in wetlands. All bladderworts are rootless. They have main stems from which lacy, often complex leaves grow. Bladderwort flowers are usually bright yellow (but sometimes lavender, depending on species); the flowers have two "lip-like" petals of about equal size. Flowers are on long stalks that emerge several inches above the water. The carnivorous bladders are attached at regular intervals along the linear leaf segments.

Clasping-leaf pondweed leaves are wide and wavy. They have a broad base that wraps around the stem. The upper part of the stem is branched and leafy with leaves alternately arranged on the stem.

Coontail is a submersed aquatic plant and can be easily identified by the "raccoon tail" cluster of leaves at the end of the main stalk. It has slender stems and leather-like leaves. Coontail is called hornwort when it is sold for aquarium decorations. It then spreads into ponds after aquariums are dumped into water bodies.

Curly-leaf pondweed leaves are somewhat stiff and crinkled, resembling lasagna noodles. They are approximately 1/2 inch wide and 2 - 3 inches long. The leaves are arranged alternately around the stem. Leaves become denser at the end of branches. Curly leaf-pondweed can be confused with clasping leaf pondweed.

Elodea grows completely submerged. It has multi-branched stems that are slightly brittle. The leaves grow in whorls. It is introduced into ponds from the aquarium industry. The flowers of Elodea have three white petals with a waxy coating that makes them float. Elodea is commonly called anacharis or common elodea.

Eurasian watermilfoil is an exotic species. Its leaves are feather-like and sometimes produce reddish flowers that extend above the water. The stems are red to brown in color. It can dominate a pond very quickly by fragmentation. Pieces of the plant grow roots to develop a new plant. There are many native milfoil plants which do not have as many feather-like leaves and are much less aggressive.

Fanwort is a submersed, floating plant with short rhizomes. The shoots are grass green to olive green or sometimes reddish brown. The leaves are either submersed or floating; submersed leaves are finely divided and arranged in opposite pairs on the stem. Floating leaves are small and inconspicuous. The floating leaves are less than 1/2 inch long and 1/3 inch wide. The leaf blade attaches to the center. The flowers are white and small and float on the water surface.

Flat-stemmed pondweed has a large stem and is flattened. The leaves are ribbon-like.

Floating-leaf pondweed has both floating and submersed leaves. The floating leaves are heart-shaped while the submersed are long and narrow.

Horned pondweed has long, linear, thread-like leaves. They are arranged in whorls on slender branching stems. Leaf tips taper to a point. It has tendril-like roots and slender rhizomes. The seeds are horn-shaped and form in the leaf axils.

Hydrilla is a submersed perennial plant with long, branching stems that can fragment to form large, dense floating mats. This plant flowers from June to July in warm climates. The flowers are small, white, and sometimes hard to spot. Hydrilla is very common in warmer climates such as those in Florida, Georgia, and Texas. Hydrilla leaves grow in whorls around the stem and have sharp, pointy edges

Illinois pondweed is similar to American pondweed, and can be easily confused. Leaves are oval in shape and float on the surface of the water, and are attached to a long stem.

Large-leaf pondweed has large, thick stems. The leaves are wavy and oval-shaped. There are leaves both below and floating on the surface of the water.

The stems of naiad species are very long and have many branches. All naiads have very narrow, inch-long leaves that have definite teeth on their margins. Southern naiad leaves are less than 1/16 inch wide. With a hand lens, very tiny teeth can be seen along the leaf margins. Naiad leaves are arranged oppositely on the stem, or sometimes in whorls of three. The leaves are deep green to purplish-green. The flowers are very small and inconspicuous. The plants have "runners" that attach all plants together allowing them to spread rapidly.

Flowers of this plant are very small and white in color. Almost all plants of this species are female. Seeds are not produced in any North American plants. Parrotfeather reproduces asexually. New plants grow from fragments of already rooted plants. There is no real predator to the parrotfeather, so it grows out of control. While part of the milfoil family, it is easily distinquishable from other milfoils as it grows below and above the surface of the water.

Sago pondweed grows from thickly matted rhizomes. It has no floating leaves. The stems are thin and have highly branched leaves, about 1/16 of an inch wide and 2 to over 12 inches long tapering to a point. The leaves grow in thick layers and originate from a sheath. The fruit is nut-like 1/8 to 1/4 inches long and 1/10 to 1/8 inches wide.

Small pondweed has several lateral branches that are attached to a slender stem. The narrow leaves are arranged alternately on the branches and taper where they attach to the stem.

Vallisneria is a submersed plant that spreads by runners and sometimes forms tall underwater meadows. Leaves arise in clusters from their roots. The leaves have rounded tips, and definite raised veins. Single white female flowers grow up to the water surface on very long stalks. Tape grass fruit is a banana-like capsule having many tiny seeds. Vallisneria has been spread from the aquarium industry.

Variable-leaf watermilfoil has long stems with whorls of finely divided leaves. This milfoil is rooted in the bottom of water bodies and arise to the surface of the water. When they reach the water, the stems turn and grow horizontally. The submerged leaves are feather-like and occur in whorls of 4 - 6. They are 1 to 2 inches long. The emersed leaves are stiff, longer than wide and have serrated margins. The flowers are small and reddish. Variable-leaf watermilfoil can reproduce by seeds or fragmentation and is an aggressive invader. Because of its tremendous growth rate variable-leaf watermilfoil can completely take over shallow ponds.