Sedges differ from grasses by having a 3-angled stem and structurally different flowers where the female flowers are enclosed in a sac like structure called the perigynium, which is subtended by a single scale. Shortbeak Sedge is a cool season native perennial sedge forming dense clumps. The flowering stems (culms) are triangular in cross-section, 6 to 48 inches high, green in color, usually smooth but within the inflorescence it may have some roughness. These rise from the rhizome and at maturity the flowering stem is much longer than the leaves. There can be non-flowering stems but these are few and inconspicuous, being shorter and developing later in the season. Stem bases have some reddish-purple coloration.
The leaf blades are light green in color, smooth, number 3 to 5 on fertile stems, flat except for a prominent mid-vein ridge which forms a V shape when young; 1.5 to 3.5 mm wide and up to 12 inches long. On non-flowering stems the leaves cluster near the tip.
Leaf sheaths are tight, white-translucent on the front, usually smooth, ligules on upper sheaths 2.2 to 3.5 mm long and U shaped. Basal sheaths have very short blades.
The inflorescence consists of a terminal spike that is gynecandrous, that is, with pistillate florets above and staminate florets below, and in this case the staminate section is well developed. The lower spikes number 3 to 6 (or 4 to 6 on larger stems), the lowest are mostly pistillate but also have a few staminate florets at their bases; sometimes these are inconspicuous; each spike is distinct but not widely separated, ovoid to ellipsoid, 7 to 17 mm long, 4 to 8 mm wide, bases narrowed to sometimes rounded, upper part pointed to rounded. The inflorescence is subtended by short green bracts that are scale-like or bristle-like, longer than the spike but much shorter than the inflorescence. The pistillate spikes have 15 to 40 perigynia, ascending to spreading. (The bladder-like sacs that enclose the female flower and later the fruit are called perigynia, singular - perigynium).
The perigynia are green or reddish brown when immature, orbiculate to broadly ovate in shape, flat on one side, convex on the other, 3.4 to 4.8 mm long by 2.3 to 3.2 mm wide and only 0.5 to 0.6 mm thick; 1.2 to 1.8 times as long as wide. They are vein-less or rarely, very faintly 1 to 5 lined on the front; leathery, with flat margins that include a small wing. The top abruptly tapering to a 2-toothed beak that usually has roughened margins, is pale green or brown at the tip. The scales on the perigynia are whitish-translucent, tinged with reddish-brown and usually with a whitish, pale gold or green mid-stripe; narrowly-ovate to broadly lanceolate in shape, narrower than the perigynium body and shorter than the perigynium beak. There are 2 stigmas.
Seed: Female flowers when mature form a dark brown achene, ovate to orbiculate in shape, 1.5 to 2.2 mm long and 1.3 to 1.8 mm wide. Florets are wind pollinated.
Habitat: Shortbeak Sedge grows from short rhizomes (elongated in old clumps) which allow vegetative reproduction forming close colonies. The sedge is found in a variety of habitats from wet-mesic to dry conditions in woodlands, meadows, prairies, and open spaces. It will grow in full sun, partial shade or full shade.
Names: The genus name, Carex, is from the Latin, being the old name for Sedges. The species, brevior, means 'shorter' referring to the shorter beak. The names of the authors for the plant classification are as follows: ‘Dewey’ refers to Chester Dewey (1784-1867), American botanist and educator, professor at Williams College and later The University of Rochester. His work in botany is known chiefly for his studies of carices - the Sedges - resulting in a 43 year series of papers titled Caricography. He published the first classification but his work was amended by ‘Mack.’ which refers to Kenneth Kent Mackenzie (1877-1934) American lawyer and amateur botanist who collected and wrote extensively on the Carex of North America. He is still the recognized author of most of the Carex species classifications. He was on the Board of Managers of the New York Botanical Garden and it received his 43,000 specimen herbarium. What he did was recognized but added to by ‘Lunell’ which refers to Joel Lunell, (1851-1920) Swedish-American botanist, whose herbarium collection was donated to the University of Minnesota.
Comparisons: Carex brevior is a member of the sedge section Ovales, which is the largest section of Carex in North America, complex and difficult in identification, with fully mature perigynia considered best for identification. C. brevior is similar to C. suberecta (Wedge-fruited Oval Sedge) but differs in its spreading perigynia. Also similar to C. molesta (Troublesome Sedge) except the inner face of the perigynium of C. molesta is finely nerved while the inner face of the perigynium of C. brevior is usually nerveless. C. molesta is found in Minnesota but not C. suberecta, which was reported once but no specimens are known. It is found in Iowa and Wisconsin.
Above: The inflorescence of Shortbeak Sedge. Drawing by Harry Charles Creutzburg ©Kenneth Kent Mackenzie (1940) North American Cariceae
Below: The terminal spike is pistillate on the top with staminate florets at the base. Note the translucency of the perigynia scales and the dark mid-stripe.
Below: Leaf blades have a prominent central ridge. 2nd photo - Sheath ligules are U shaped. 3rd photo - The back of the sheath is green, longitudinally lined.
Below: The inflorescence during flowering and after. Note that most of the lower spikes have a few staminate flowers with anthers exposed.
Below: 1st photo- the base of the stems have some reddish-purple coloring and the basal sheaths have very short blades. 2nd photo - spikes forming. 3rd photo - the mature perigynia clearly show the flat marginal wing (photo ©USDA-NRCS PLANTS Database / Hurd, E.G., N.L. Shaw, J. Mastrogiuseppe, L.C. Smithman, and S. Goodrich. 1998. Field guide to Intermountain sedges. USDA Forest Service.).
Below: Perigynia at two stages of maturity.
Shortbeak Sedge is one of over 150 sedges native to Minnesota. It is fairly widespread in Minnesota, with a minority of counties not reporting it in the DNR surveys - most of those in the north-central part of the state from Todd county up to Roseau County. In North America it is widespread, found in all the lower Canadian Provinces except the maritime, and in the U.S. it is found throughout except for the very SE Atlantic states and in the west it is absent in Oregon, Calif., Nevada and Utah.
It has not been noted on any previous Garden Plant Census until recently as Susan Wilkins planted it in 2009.
References: Plant characteristics are generally from sources 1A, 32, W2, W3, W7 & W8 plus others as specifically applied. Distribution principally from W1, W2 and 28C. Planting history generally from 1, 4 & 4a. Other sources by specific reference. See Reference List for details.
Identification booklet for most of the flowering forbs and small flowering shrubs of the Eloise Butler Wildflower Garden. Details Here.
Friends of the Wild Flower Garden, Inc. Text and photos are by G. D. Bebeau unless otherwise credited. "www.friendsofthewildflowergarden.org"