Weed Identification


Welcome to SePRO's Aquatic Weed Identification Guide. This guide will serve as your first step toward identifying and managing your aquatic weed problem. To get started, click on whichever group of aquatic weeds to which you feel your problem weed belongs and work through the examples until you find it.



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Hydrocotyle umbellata

Dollarweed is also referred to as pennywort. The leaves are round in shape and approximately one inch in diameter. The leaves are dark green and glossy with scalloped edges. The petiole of pennywort is attached to the center of the leaf. The flower is small with five white petals and forms in clusters on the end of long stems. Dollarweed spreads by seed and rhizomes.

Also known as: Pennywort; navelwort; many flowered pennywort


Lemna minor

Duckweed is a very small floating plant. It has shoe-sole shaped leaves with a small hair-like root hanging on its underside. It resembles a four-leaf clover and is approximately the size of a pencil eraser. It is frequently misidentified as algae. Once established, it can cover the entire water surface and resemble a golf course green. It can cut off sunlight to submersed plants and cut off oxygen to fish and other wildlife.

Also known as: Duck's meat; Duck meal


Elodea canadensis

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.

Also known as: Anacharis; ditch moss; water thyme; waterweed; Brazilian Elodea

Eurasian Watermilfoil

Myriophyllum spicatum

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.

Also known as: Spiked watermilfoil