Five common grasses and sedges of Scotts Bluff National Monument's prairie

The presidential proclamation that created Scotts Bluff National Monument in 1919 also set its original boundaries, which preserved some of the best native prairie in the region, prairie relatively untouched by human disturbance. Natural prairie grasses are the main vegetation on the monument's more level ground. About 40 percent of the monument's 3,003 acres is mixed-grass prairie, dominated by two cool-season species, threadleaf (blackroot) sedge and needle-and-thread grass, which together make up 82 percent of the ground cover. Other common native grasses of the prairie are western wheatgrass, junegrass, blue grama, prairie sandreed, little bluestem and side-oats grama.

The seed awns of needle-and-thread grass are distinctive and give the species its name. NPS/Eric Grunwald.

Needle-and-thread grass

Hesperostipa comata is a native, perennial, cool-season bunchgrass: it lives for several years and grows in clumps rather than forming mats of turf. It stands one to four feet tall. Its most distinctive feature is the twisted awns, bristle-like appendages four to five inches long, attached to the seeds. The awns are hygroscopic, meaning they absorb moisture from the air, and when they do they untwist slightly, which lets the sharply pointed seed head drill itself into the ground.

Threadleaf sedge is one of the dominant plants of the Scotts Bluff prairie. NPS image.

Threadleaf (blackroot) sedge

Carex filifolia is technically not a grass. Sedges, like grasses, tend to form clumps, but they have three-sided stems. Threadleaf sedge is a cool-season, drought-resistant, low-growing native perennial that looks like a grass. It grows in bunches four to six inches wide, with hollow stalks two to fifteen inches tall. Its numerous tough, wiry roots do not tend to grow deep but spread two to two and a half feet away from the plant.

Blue grama is sometimes called "eyelash grass" because of its comb-like structures. NPS image.

Blue grama

Bouteloua gracilis is a native warm-season grass. In some parts of its range it forms sod, but at Scotts Bluff it forms bunches. It grows six to 24 inches tall and sends out a prolific root system. Its most distinctive feature is the comb-like spikes at the ends of the stems, which somewhat resemble eyelashes and give it the nickname "eyelash grass." The spikes bear flowers which, if pollinated, produce oblong-elliptic brown seeds 2.5 to 3 mm long.

Look closely at the zig-zagging stems of sideoats grama. NPS/Eric Grunwald.

Sideoats grama

Bouteloua curtipendula is a native, perennial, clump-forming, warm-season grass 12 to 42 inches tall. Its small, oat-like seeds dangle from the sides of its zig-zagging stalks. Deer, elk and other mammals graze its leaves, and several species of birds eat its seeds.

Little bluestem leaves turn a distinctive coppery red in fall. NPS/Eric Grunwald.

Little bluestem

Schizachyrium scoparium is a native, warm-season, clump-forming grass. Its leaves grow in clumps one to two feet high until late summer, when it sends up flowering stems that can reach five feet. As the name suggests, young leaves are bluish, but by fall they turn an attractive copper color.

Deer browse the leaves, and grasshoppers, beetles, spittlebugs, leafhoppers and other plant-eating insects feed on the plant. Bumble bees, the caterpillars of at least one species of skipper, and several small mammal species may spend the winter in the sheltered space at the base of the clumps.

Sources

• National Park Service, Scotts Bluff National Monument, Common Grasses of Scotts Bluff National Monument; the photographs are credited as printed; the source's sideoats grama paragraph names blue grama as the early-greening browse plant, which contradicts its heading, so that sentence is left out, and the misspelled scientific name of sideoats grama is corrected to Bouteloua curtipendula; rewritten in hubnx's own words.