perennial sedge is 1-2¾' tall, consisting of a tuft of leaves and
an unbranched culm that is erect, ascending, or leaning to one side.
The culm is light green, 3-angled, and glabrous; it is slightly rough
along the angles below the inflorescence. Several alternate leaves
occur along the lower one-fourth of the culm; their blades are
ascending to widely spreading and recurved. Leaf blades are up to 12"
long and 2-4.5 mm. across; they are light green, glabrous, furrowed,
and slightly rough along their margins. Individual leaf sheaths have
one side that is translucent-membranous and 2 other sides that are
green and glabrous; they wrap around the culm tightly. Below the
concave mouth of each sheath, its translucent-membranous side is
somewhat stiff and thickened. Each culm terminates in an inflorescence
that is ¾-1½" long and up to ½" across; it consists of 4-10 sessile
spikelets that are overlapping to slightly separated. Some spikelets
have a few staminate (male) florets and their scales at their apices,
while the perigynia of pistillate (female) florets and their scales are
located below. Other spikelets consist entirely of the perigynia of
pistillate florets and their scales. Each spikelet has 6-16 ascending
to widely spreading perigynia that are clustered together. The
perigynia are 3.0-4.0 mm. in
length, 2.0-3.0 mm. across, and
plano-convex; they are ovate-orbicular in shape, tapering to a short
beak with 2 minute teeth. For the typical variety of Sand Sedge, the
perigynia have several longitudinal veins along their outer sides,
while for var. enervis
the outer sides of the perigynia are veinless.
The perigynia are glabrous and they vary in color from light green to
yellowish brown. The pistillate scales are about the same length as the
perigynia or a little shorter; they are ovate in shape, tapering to
short awn-like tip. The pistillate scales have green central veins and
membranous margins. Each female floret has a pair of yellowish brown to
stigmata. At the base of each inflorescence, there is a slender leafy
up to ¾" in length; one or two additional bracts of smaller size may
occur within the inflorescence. The blooming period occurs from late
spring to early summer, lasting about 1-2 weeks. The florets are
cross-pollinated by the wind. Afterwards, the mature perigynia
disarticulate from the spikelets and they are blown about by the wind.
Individual achenes are about 2.0 mm. in length, ovoid-orbicular in
shape, and somewhat flattened, tapering abruptly to a small point at
their bottoms.. The root system is short-rhizomatous and
The preference is full or partial sun, mesic to dry
conditions, and sandy soil.
The native Sand Sedge is occasional
Habitats include upland sand prairies, sand
dunes, rocky upland woodlands, areas along railroads, and sandy
fields. There is a preference for upland habitats with barren soil and
reduced competition from other kinds of ground vegetation.
Various insects feed on sedges (Carex spp.
upland areas. These species include such common aphids as Rhopalosiphum
(Corn Leaf Aphid), Schizaphis graminum
(Spring Grain Aphid), and
(Yellow Sugarcane Aphid). An introduced aphid, Iziphya
, has been found on Sand Sedge (Carex muehlenbergii
specifically in Mason County, Illinois. Many grasshoppers feed on the
foliage of upland sedges and other plants. These species include Arphia pseudonietana
(Narrow-Winged Sand Grasshopper), Spharagemon
Grasshopper), and Trachyrhachys
(Kiowa Grasshopper). See the Grasshopper Table
for a more complete list of
these species. Some billbugs also feed on sedges and similar species;
they include Sphenophorus
(Southern Corn Billbug), Sphenophorus costicollis
(Sedge Billbug), and Sphenophorus
The larvae of billbugs usually burrow through the stalks of these
plants. Among vertebrate animals, upland gamebirds and granivorous
songbirds feed on the seeds of upland sedges. These species include the
Greater Prairie Chicken, Ring-Necked Pheasant, Wild Turkey, Horned
Lark, Snow Bunting, and others (see the Bird Table
list of these species). A small mammal, the Prairie Vole, feeds on
either the foliage or seeds.
A sand dune at the
Oak Openings Nature Preserve
in NW Ohio.
Sometimes the scientific name of this sedge is spelled Carex
. Other common names of this sedge are
and Sand Bracted Sedge. The typical variety of Sand Sedge is more
common in Illinois than var.
. Mohlenbrock (1999/2011) now
classifies var. enervis
as a distinct species, or Carex
. In the
past, Carex austrina
(Southern Sedge) was regarded as a variety (var.
) of Sand Sedge, but it is currently classified as
species. Considering the variations in taxonomy around this species, it
is not surprising that this sedge can be difficult to distinguish from
other similar sedges, such as Carex
(Heavy Sedge) or Carex
(Midland Sedge). However, it is more likely to
be found in
sandy habitats than these latter two species.