Description: This native sedge is a summer annual about 2-6" tall. It sends up several stems from the base, otherwise it is unbranched. The culms are up to 4" long, light green, hairless, and usually 3-angled. There are 0-3 alternate leaves along each culm when the flowers bloom (older leaves become brown and withered). The leaf blades are up to 3" long and about 1/8" across; they are light green, glabrous, linear, and indented along their central veins.
Each culm terminates in 1-3 sessile heads
of spikelets; on rare occasions, heads of spikelets may be produced on short
stems up to ½" long. Each head consists of several spreading spikelets.
Each spikelet is about ¼" long and flattened, consisting of 6-10 flowers
in two columnar ranks. Each flower is enclosed in a single keeled scale; this
scale is light green, hairless, and lanceolate, tapering into a recurved tip.
The flower is without petals and sepals, consisting of a single anther and a
tripartite deciduous style that is barely exerted from its scale. At the base
of the heads of spikelets, there are 2-3 leafy bracts that are up to 3" long;
these bracts are light green, glabrous, and linear like the leaves. The
blooming period usually occurs from mid-summer to early fall. The flowers are
wind-pollinated. As the achenes mature, the floral scales turn light brown;
each flower produces a single 3-angled achene that is about 1 mm. in length.
The root system consists of a shallow tuft of fibrous roots. This sedge often
forms colonies in suitable habitats; it reproduces by reseeding
itself.
Cultivation: The preference
is full or partial sun and wet to moist conditions; this sedge grows in
different kinds of soil, including those that are sandy, thin and rocky, or
mucky. It dislikes competition from taller plants.
Range & Habitat: Bearded Flat Sedge occurs
occasionally in central and northern Illinois, while in the southern part of
the state it is less common. While this sedge is widely distributed, its
populations tend to be scattered and local. Bearded Flat Sedge also occurs in
Eurasia and South America. Habitats include low-lying areas along rivers and
ponds, prairie swales and sedge meadows, seeps, swampy woodlands, depressions
in sandstone glades, crevices of sandstone cliffs, moist fields, and cracks
along sidewalks and parking lots. This sedge typically occurs in wet areas with
low vegetation, although it adapts as well to dry rocky areas (whether natural
or artificial) where there are pockets of moisture. One reason that this sedge
can adapt to such dry habitats is its C4 metabolism – this is the same
metabolic pathway that enables warm-season prairie grasses to survive Illinois'
hot dry summers!
Faunal
Associations: The caterpillars of Glyphipterix impigritella
(Flat Sedge Borer Moth) bores into the stems of Cyperus spp. (Flat
Sedges). The seeds of Flat Sedges are eaten to a limited extent by some wetland
birds, including the Green-Winged Teal, Bobolink, and Wilson Snipe. The Canada
Goose also eats the foliage.
Photographic
Location: This little sedge was growing abundantly in the cracks
between a sidewalk and parking lot in Champaign, Illinois.
Comments: Bearded Flat Sedge is easy to identify
because its floral scales have strongly recurved tips. As a result, the
spikelets have an odd saw-toothed appearance along their margins. The foliage
and spikelets of young plants have a fresh spring-time appearance that is
unusual for anything that grows during the middle of summer. Other Cyperus
spp. (Flat Sedges) tend to be larger plants that produce their heads of
spikelets on stalks; their floral scales lack recurved tips and these scales
are usually some shade of yellow, red, or brownish purple during the blooming
period. The floral scales of Bearded Flat Sedge are light green until after the
blooming period is over, then they become light brown. Other scientific names
that have been assigned to this species include Cyperus aristatus and
Cyperus inflexus.