Prairie Cordgrass

Prairie cordgrass growing against a blue sky
Scientific Name
Spartina pectinata
Poaceae (grasses)

Prairie cordgrass is a native perennial sod-forming grass with flowering stalks up to 7 feet tall. Rootstocks are stout, widely creeping, scaly rhizomes that typically grow into dense, tangled sod. The leaf blades are coarse, 12–30 inches long, and about ¼–½ inch wide, flat, slightly corrugated, or (when dry) the edges rolling inward. Leaf edges are sharply toothed or roughened. Mature seed heads contain 7–30 spikes (clusters) arranged pinnately along the sides of the stem. Each spike is 1–5 inches long, with 15–80 closely spaced spikelets (florets) arranged on one side of the axis (small stalk they grow on). The spikes and the spikelets stand upright or are slightly angled. Seeds are often not produced. When they are, and the seeds fall away, their axes remain on the main stalk. Flower heads develop June–September.

Habitat can be a helpful identifier. Prairie cordgrass grows in dense stands in low, damp soils. It’s often called ripgut because of the tiny sharp saw teeth on the leaf edges.

Similar species: Be aware there are other plants with some of the same common names. For example, there is a species called ripgut grass, ripgut brome, or great brome (Bromus diandrus); it is a Mediterranean native that has been introduced to North America. It is a great problem in western states. It has been found in a few Missouri locations, near railroads or other disturbed areas. Its seeds have sharp-pointed tips and are covered with small, backward-pointed hairs that work like fishhooks; they are a danger to animals, as the seeds get caught in fur and work their way into the skin. This species doesn’t look or grow like cordgrass.

You might be wondering if cordgrass, with its sawtoothed leaves, is the same thing as the famous sawgrass that grows extensively in the Florida Everglades: It isn’t. The Everglades sawgrass (Cladium mariscus ssp. jamaicense) is actually a sedge and is not a true grass. It rarely occurs in Missouri; it was first recorded from a single location in Missouri in 2012.

Other Common Names
Slough Grass
Prairie Cord Grass
Marsh Grass

Height: flowering stems 3–7 feet.

Where To Find

Common to scattered nearly throughout Missouri. Less common in some parts of the Ozarks and Bootheel lowlands. It has a broad North American distribution.

Occurs in bottomland prairies, moist depressions of upland prairies, marshes, sloughs, and margins of ponds and lakes; also on roadsides, railroads, margins of crop fields, and disturbed, moist areas. The common names “marsh grass” and “slough grass” can help you remember that this species lives in low, wet soils.

This fast-growing species often forms large colonies, but once established, seed production is frequently low.

Tall native perennial warm-season clump- and sod-forming grass.

Prairie cordgrass, when young, is good grazing for livestock, and it is also acceptable for hay, if cut before the tough stems form. Older plants are too tough to be used for forage.

Many writers have described the sharp teeth along the margins of the leaves. John Madsen, in Where the Sky Began, said the serrations had “a stiff wire edge like a good butcher knife. Before I learned to wear gloves while cutting mature sloughgrass for dog bedding, I used to wonder who was harvesting whom.” He continued, “When cured, however, it’s useful for livestock bedding because it doesn’t break down easily. I’ve never found anything better for a dog kennel. All in all, useful stuff.”

Today, people cultivate prairie cordgrass in rain gardens or near ponds and in places where they want to prevent erosion, such as on wet slopes and along streams. This tough native grass forms large colonies and holds the soil well.

With only a little practice, you can learn to see this species from a distance. Early prairie settlers knew that if prairie cordgrass was growing in an area, then that area was prone to flooding, and the heavy, wet soils beneath the cordgrass would be unsuitable for plowing. People driving wagons avoided places where they could see cordgrass growing, to avoid squishy wet soils that could bog down their wheels.

Prairie cordgrass, however, was very useful for settlers. In addition to using it as livestock forage and hay, they learned from Native Americans how to use cordgrass for thatching roofs and keeping the rain off of haystacks and corncribs.

Perhaps the most important use for prairie cordgrass was for human habitation. In the middle of the once-vast, treeless expanse of America’s Great Plains, pioneers had very little wood for construction. Many people built homes out of prairie sod, and cordgrass sod was a favorite: it forms a dense, interconnected mass of tough, woody rhizomes. Settlers cut the sod into 1-by-2-foot rectangles and used these like adobe bricks to construct homes with weatherproof walls two feet thick. These were cavelike and cool in the summer and insulated enough to retain heat in the winter. The pole-framed, lightly sodded roof was often finished with a thatch of cordgrass. The sod houses, or soddies, of the early prairie settlers are a memorable chapter in American history. When trains arrived, people had access to lumber, and new sod construction ended. But people still lived in them into the 20th century, and some examples still survive; some are on the National Register of Historic Places.

Missouri author Laura Ingalls Wilder wrote of living in a sod home in the 1870s in her autobiographical novel On the Banks of Plum Creek. She described that home, located near Walnut Grove, in southwestern Minnesota, calling it a "dugout." She does not specify that prairie cordgrass was a major component of the sod home, but the species is common in Minnesota and was probably among the plants whose tough root systems created the front wall and roof of the home.

In lands with very few trees, what did the early prairie settlers use for fuel? They (or, more likely, their children) twisted the tough, woody stalks of cordgrass together into bundles and burned these in stoves for cooking and warmth. In cold northern states and provinces, the toughest and woodiest prairie grasses were stockpiled for possible use for winter heating.

Researchers are studying prairie cordgrass as a possible source for biofuel.

The dense colonies of prairie cordgrass prevent soil erosion. In a ring around a pond or wetland, cordgrass often grows in the low, damp soils just outside the realm of the cattails and sedges. Together, cordgrass, sedges, and cattails generally hamper erosion and catch sediment and organic materials, building up soils and reducing the area covered by water.

Among woody plants, there are several types of trees that are famous for occurring in low, wet areas — think of sycamores, willows, and cottonwoods that follow the course of creeks. In grasslands, prairie cordgrass does about the same thing, following the streams and soggy areas at the lowest valleys of the landscape.

A number of insects use prairie cordgrass as their major or perhaps only food plant, including at least four types of moths, three types of leafhoppers, a seed bug, a plant bug, a weevil, a toothpick grasshopper, and a number of thrips. These various insects, some of which eat the developing seeds, might be one reason why large, established colonies frequently produce low numbers of seeds.

As a wetland-border plant, prairie cordgrass is important for a number of geese, ducks, and other waterfowl, which may eat the seeds or roots. It also provides them with cover and shade.

Deer, and historically, other grazing animals such as bison and elk, graze on the young foliage. Muskrats and other herbivorous rodents also eat the greenery and enjoy the dense cover cordgrass provides.

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About Wildflowers, Grasses and Other Nonwoody Plants in Missouri
A very simple way of thinking about the green world is to divide the vascular plants into two groups: woody and nonwoody (or herbaceous). But this is an artificial division; many plant families include some species that are woody and some that are not. The diversity of nonwoody vascular plants is staggering! Think of all the ferns, grasses, sedges, lilies, peas, sunflowers, nightshades, milkweeds, mustards, mints, and mallows — weeds and wildflowers — and many more!