Description:
This perennial sedge is 2-4' tall, consisting of a loose tuft of leafy
culms. The culms are light green, 3-angled, and glabrous. About 3-6
alternate leaves occur along each culm; their blades are ascending to
widely spreading. The leaf blades are up to 13" long and 12 mm. across;
they are light to medium green, grooved, glabrous, and rough along
their margins. The 2 outer sides of the leaf sheaths are light green,
longitudinally veined,
and glabrous, becoming reddish brown toward the base of each culm. The
inner side of the leaf sheaths is more membranous, tending to
deteriorate with age. The
lowest leaves of each culm consist of sheaths without significant
blades. Each
fertile culm terminates in an inflorescence consisting of 1-3 staminate
spikelets, 2-6 pistillate spikelets, and their leafy bracts.
Both staminate and pistillate spikelets droop from slender
peduncles; the staminate spikelets are located above the pistillate
spikelets. Some spikelets with primarily staminate florets
and scales may have a few pistillate florets, perigynia,
and scales toward their tips (gynecandrous). Similarly, some
spikelets with pistillate florets, perigynia, and scales may have a few
staminate florets and scales at their tips.
The
staminate spikelets are ¾-4" long and very narrow; they are whitish
green while immature, becoming tan at maturity. The pistillate
spikelets are 1½-4" long and narrowly cylindrical; they are whitish
green while immature, becoming bronze-colored at maturity. The
peduncles
of the staminate and pistillate spikelets are ¼-2½" long and glabrous.
The perigynia are 2.5-4 mm. in length and 1.5-3 mm. across; they are
broadly ellipsoid to obovoid, slightly flattened, glabrous, and
veinless. Sometimes the perigynia are slightly crimped along one side.
Each
perigynium tapers abruptly to a minute beak from which the stigmata are
exerted. The pistillate scales are 6-12 mm. in length; they have
short oval bodies with long awn-like tips. Minute teeth occur along
both sides of their tips. The oval body of each pistillate
scale may be slightly indented near the base of the awn-like tip,
otherwise its upper surface is jagged-truncate or rounded.
The blooming period occurs from late spring to mid-summer, lasting
about
1-2 weeks. The florets are cross-pollinated by wind. At maturity, the
perigynia disarticulate from their spikelets, beginning at the tips;
they have the capacity to float on water, distributing their achenes to
new locations. The achenes are about 1.5 mm. long, obovoid in shape,
and
somewhat flattened; they are sometimes slightly crimped along one side.
The root
system is fibrous and rhizomatous. This sedge often forms colonies of
plants.
Cultivation:
The preference is light shade to full sun,
wet to moist conditions, and soil containing loam, sand, clay, gravel,
or peaty material. Some seasonal flooding is tolerated. This is a
rather lanky sedge that leans to one side as the spikelets develop.
Range
& Habitat: The native Fringed Sedge is occasional
in southern
Illinois, NE Illinois, and west-central Illinois, while in the rest of
the state it is rare or absent (see
Distribution
Map).
Habitats consist
of a wide variety of wetlands, including prairie swales, sandy sloughs,
sedge meadows, wet prairies, wet dolomite prairies, marshes, gravelly
seeps, swamps, bogs, borders of small lakes, and ditches. This sedge is
also found in damp areas of bottomland woodlands.
Faunal Associations: Sedges (
Carex spp.)
are ubiquitous in wetland
areas and many insects are adapted to feed on them in these habitats.
These species include leaf beetles (primarily
Plateumaris spp.),
Sphenophorus costicollis
(Sedge Billbug), the seed bugs
Cymus
angustatus and
Oedancala
dorsalis, the
shield bug
Eurygaster
alternata, aphids and
leafhoppers, the spittlebug
Philaenus
parallelus, stem-boring larvae of the flies
Cordilura varipes
and
Loxocera cylindrica,
larvae of the shore fly
Hydrellia
griseola (Lesser Rice Leafminer), caterpillars
of moths, caterpillars of skippers (
Euphyes
spp.,
Poanes
spp.), caterpillars of the butterfly
Satyrodes eurydice
(Eyed Brown), and sedge grasshoppers (
Stethophyma
spp.). The
Insect Table lists
many
of these species. Some vertebrate animals also use wetland sedges as a
source of food. Ducks, rails, and other wetland birds feed on the seeds
or spikelets (see
Bird Table),
while such turtles
as
Chelydra
serpentina (Snapping Turtle) and
Kinosternum
subrubrum (Eastern Mud Turtle) feed on the spikelets or
foliage (Ernst et al., 1994). Among
mammals, muskrats eat the culms, roots, or sprouts of wetland sedges
occasionally, while such mammals as the White-Tailed Deer
and Black Bear feed on the foliage or spikelets very sparingly.
Photographic
Location: A sandy ditch along a railroad at the Indiana
Dunes National Lakeshore in NW Indiana.
Comments:
Fringed Sedge is readily identified by its abundant drooping spikelets
and the bristly appearance of those spikelets from the awn-like tips of
the pistillate scales. It is a rather variable species across its range
and different varieties have been described. In Illinois, the typical
variety,
Carex crinita
crinita, is the most common by far. Another
variety,
Carex crinita
brevicrinis, has been found in southern
Illinois, where it is rare. This latter variety has larger perigynia,
shorter tips on its pistillate scales, and achenes that are never
crimped along one side. Another variety,
Carex crinita gynandra,
has
been found in southern Illinois recently, where it is rare. Sometimes
this variety is regarded as a distinct species,
Carex gynandra
(Fringed
Look-Alike Sedge). This variety (or species) differs from the preceding
varieties of Fringed Sedge by its pistillate scales: the bodies of
these scales are more narrow (ovate or lanceolate in shape) and they
taper gradually to their awn-like tips, instead of tapering
abruptly by forming indentations or jagged-truncate upper surfaces (see
Mohlenbrock, 1999/2011, for more detailed information).