Plant of the Week

Map of the United States showing states. States are colored green where the species may be found.
Range map of Carex varnacula. States are colored green where the species may be found.

Carex varnacula.
Carex varnacula. Photo by Russ Holmes.

Carex varnacula.
Carex varnacula. Photo by Russ Holmes.

Close up of Carex varnacula flower.
Carex varnacula. Photo by Russ Holmes.

Carex varnacula habitat.
Carex varnacula habitat. Photo by Russ Holmes.

Native Sedge (Carex vernacula)

By Russ Holmes

Native sedge is in the Cyperaceae (sedge) Family which contains slightly over 100 genera and approximately 5,000 species worldwide occurring mostly in temperate and cold climates. Species in the family have limited economic importance though some are used as ornamentals. The real value of species in this family is found in the ecological function they perform. Carex species play a very important role in stabilizing soils in prairies, along streambanks and in wetlands. As much as 75% of sedge biomass has been estimated to occur below ground. Sedges also provide streamside habitat for invertebrates. Sedges serve as the foundation for both terrestrial and aquatic food chains and are a source of forage for butterfly caterpillars, waterfowl, and a wide variety of mammals including voles, ground squirrels, prairie dogs, beavers, muskrats, pikas, rabbits, bears, bighorn sheep, bison, musk ox, moose, elk, reindeer, and deer. Native Americans historically used sedge leaves to make rope and both leaves and rhizomes for making baskets, mats and clothing.

Native sedge is loosely clustered (cespitose) or short rhizomatous. Culms are 8 to 40 centimeters (3.1 to 15.7 inches) tall and support a dark, dense, truncate inflorescence. The individual spikes of the inflorescence are so densely crowed that they are indistinguishable. The leaves are all basal, shorter than the culms, and flat. Perigynia (specialized bracts that encloses the fruit) are pale yellow brown at the base becoming reddish brown above. They are narrowly to broadly elliptic and include a short basal stipe 0.2 to 0.6 millimeters (0.008 to 0.02 inches) long. Stigmas are two. Achenes (fruits) are lenticular.

The species is distributed in the western United States extending from the state of Washington south to California and east to Wyoming and Colorado. It is rare in the Pacific Northwest. Habitat is found in alpine and subalpine settings between 2,000 and 3,800 meters (6,600 to 12,500 feet) in wet meadows, along the margins of headwater streams and lakes and on rocky slopes that receive snowmelt.

A few western states have considered using native sedge for roadside erosion control. The green basal leaves, dark dense heads and clustered habit make it an attractive addition to the mix of vegetation and helps illustrate the value of using native species in restoration projects.

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Louisiana Trillium (Trillium ludovicianum).
Louisiana Trillium (Trillium ludovicianum)