Description: This native perennial sedge
is about 1½–2½' tall. It is often tufted at the base,
sending up multiple culms and leaves. Vegetative shoots are less common and
conspicuous than fertile shoots. Each culm is unbranched, slender, and rather
stiff. It is light green to green, 3-angled, hairless, and smooth, except near
the inflorescence, where its texture is often rough. Each fertile shoot has
about 3 alternate leaves, which are located on the lower-third of the culm. The
individual leaf blades are about 5-10" long and 3 mm. across; they are light
green to green, hairless, and ascending to spreading. The sheaths are whitish
green, veined, and hairless; they adhere tightly to their culms. The upper
mouth of each sheath is concave and membranous. Each culm terminates in a short
inflorescence up to 2" long. This inflorescence consists of about 3-6 spikelets
that are nearly sessile. The slender stalk of each inflorescence can be
straight or nodding. Each spikelet is up to 15 mm. long and 5-7 mm. across; it
is ovoid in shape and either rounded or club-shaped (clavate) at the bottom.
Spikelets with abundant staminate florets tend to be longer and more
club-shaped than those with few or no staminate florets. Each spikelet has
numerous spreading to ascending perigynia. Each perigynium is about 5-6 mm.
long and 4 mm. across; it is broadly ovoid, flattened, rounded at the bottom,
and with a beak at the top. There are several distinct veins on both sides of
the perigynium, and its margins are winged. Immature perigynia are light green,
but they later turn brown. The pistillate scales are about 3 mm. long, 1 mm.
across, and lanceolate in shape; they are shorter than the perigynia. Each
pistillate scale has a central green vein and membranous margins; it later
becomes tan or brown. The lowest bract of the inflorescence is about ½"
long and narrowly linear in shape; it is sometimes absent. The blooming period
occurs during late spring, while the achenes become mature during the summer.
They are distributed to some extent by the wind. The individual achenes are
about 2 mm. long and 1.5 mm. across; they are ovoid and flattened. The root
system is fibrous and rhizomatous.
Cultivation: The preference is full sun and mesic to
dry conditions. Various kinds of soil are tolerated, whether fertile or
non-fertile. This sedge adapts to cultivation in a sunny garden, but it resents
competition from tall broad-leaved forbs.
Range & Habitat: Bicknell's Sedge is occasional in central and northern Illinois, and uncommon to absent in the southern section of the state (see Distribution Map). Habitats include moist to dry prairies, barren rocky areas with scant vegetation, thinly wooded slopes, and savannas. This sedge is usually found in high quality natural habitats.
Faunal Associations: This sedge and others provide food for various insects and birds. In particular, various sparrows and upland gamebirds eat the seedheads of this upland sedge, while the caterpillars of some skippers and other lepidoptera feed on the foliage (see the Bird Table and Lepidoptera Table for lists of these species).
Photographic
Location: Cemetery prairies near Paxton and Loda, Illinois. The
spikelets in the upper photograph have more than the usual number of staminate
florets for this species.
Comments:
This species is sometimes referred to as the 'Prairie Sedge' because of its
preference for this kind of habitat. It is in the Ovales Section of Carex
spp. (Sedges), which are usually difficult to distinguish from each other.
However, Bicknell's Sedge has larger perigynia than the others (about 6 mm.
long & 4 mm. across).