Learn which plants thrive in your Hardiness Zone with our new interactive map!

Marsh Plant Identification

By John Lindell ; Updated September 21, 2017

There are different types of freshwater marshes, and the plants that grow within them provide the main distinction between these marshes. Some marshes are deeper than others are and have less vegetation, while others have such plants as sawgrass, water lilies, cattails and arrowhead as their principle flora. These marsh plants have specific features that an individual may observe that will allow someone to make identification.


Arrowhead is a typical marsh plant that can grow in the shallow waters. Arrowhead has trianglular leaves that have obviously pointed ends, which give the plant its name. The stem will appear to have five separate sides when someone picks it and cross-sections it. Arrowhead has white flowers that grow in threes on the stalk. The leaves of arrowhead will develop in clusters at the bottom of the plant and can be as long as four feet in some types but are usually in the two to four-foot range.


The cardinal flower is an outstanding marsh plant because of the bright red color of its tubelike flowers, which normally bloom during the summer months into early fall. The cardinal flower has elliptically shaped leaves and the flowers grow in spikes up and down the stem, which grows to heights of four feet. These gaudy blooms are so showy that the flower is now uncommon in some parts of the country, since people feel compelled to pick them.


Cattails are perhaps the easiest of the marsh herbs to identify, as they possess the features that give them their peculiar name, a brown spike on the top of the plant. Besides looking like a feline’s tail, this spike, which is the female flower of the plant, resembles a hot dog impaled lengthwise from a distance. Cattails tend to grow in close stands so thick that it is difficult to navigate through them. They can reach heights of 10 feet and come in two types in the U.S., the narrow-leafed cattail and the broad-leafed cattail, with their names giving away the characteristics of the leaves.


Sawgrass is characteristic of brackish water and can develop into an area so thick that it is nearly impenetrable. The plant, which can grow well over a man’s head, forms from a root system of rhizomes, which spread underwater or on dry ground with the grass shooting up from this elaborate network. As its name suggests, sawgrass has leaves so sharp that they can act like a saw, especially on the skin of an unsuspecting person trying to find his way through to access a fishing spot or while paddling in a canoe.

Invasive Species

Water lily

The water lily is an aquatic plant native to the East that in some marshes is the only type of vegetation in the water. It has the ability to take over a marsh setting, spreading by means of its rhizomes. The plant will develop from a long stalk that comes to the surface and then turns into a broad green leaf with a notch in it that brings to mind a green “pac-man.” The flower is very impressiv--white or pinkish and with multiple petals. However, for all their beauty, the water lily is an invasive species in many areas, as it now exists across the nation. It grows in such dense patches that it can clog waterways, crowd out other native water plants and deplete the oxygen level in a marsh under its broad leaves.


About the Author


John Lindell has written articles for "The Greyhound Review" and various other online publications. A Connecticut native, his work specializes in sports, fishing and nature. Lindell worked in greyhound racing for 25 years.