Sedge family (Cyperaceae)
Description: This native perennial sedge is 12½' tall, consisting of a dense tuft of leafy culms. Both fertile and some infertile shoots are present; the latter have more leaves. Each fertile culm is erect to ascending; it has 2-3 alternate leaves along the lower 1/3 of its length (also dried remnants of older leaves). The stiff slender culms are light to medium green, glabrous, and 3-angled. The leaf blades of fertile shoots are about 4-8" long and up to 3 mm. across; blades of vegetative shoots are somewhat longer. The typical blade is ascending at the base and curves outward toward the middle; it is light to medium green, glabrous, channeled along the middle, and rough-textured along its margins. The sheaths are tight and hairless; the inner side of each sheath is membranous, while the outer 2 sides are light to medium green and longitudinally veined. Each fertile culm terminates in an inflorescence consisting of 2-4 sessile spikelets; these spikelets are clustered closely together (collectively spanning about 1½2½ cm. in length). Each spikelet is 7-9 mm. long and 6-7 mm. across; it is globoid-ovoid in shape, consisting of a dense cluster of widely spreading to ascending perigynia and scales. Most florets are female, although some toward the bottom are male. Both the bottom and apex of each spikelet is well-rounded. Each perigynium is 3.54.5 mm. long and 2.02.5 mm. across; it is ovoid with a long beak, rounded at the bottom, flattened (plano-convex), and membranous along its margins. There are several longitudinal veins on the outer surface, while the inner surface has a few fine veins that are difficult to see. Immature perigynia are whitish green, while mature perigynia become brown. The pistillate scales are shorter than the perigynia and lanceolate-oblong in shape; each of these scales is green-veined in the middle and broadly membranous along the margins. The bracts of the inflorescence are scale-like or absent. The blooming period occurs during the late spring. The achene-bearing perigynia are blown about by the wind or float on water, thereby distributing the achenes to new locations. Each small achene is about 1.5 mm. long, 1.0 mm. across, lenticular (ovoid & flattened), and usually with a small point at the bottom. The root system is fibrous and short-rhizomatous.
Cultivation: The preference is full or partial sun and wet to mesic conditions. This sedge adapts to soil containing loam or clay-loam; in open areas, it is slightly aggressive and weedy in open situations.
Range & Habitat: Troublesome Sedge is common in central and northern Illinois; in southern areas of the state, it is occasional or absent (see Distribution Map). This sedge adapts to a wide variety of habitats, including wet to dry-mesic prairies, open woodlands, swamps, thickets, abandoned fields, wet depressions in sunny areas, degraded wetlands, and roadside ditches. This sedge is often found in habitats with a history of disturbance.
Faunal Associations: Several species of butterflies, skippers, and moths feed on Carex spp. (sedges); the Lepidoptera Table lists many of these species. Other insects also feed on sedges, including leaf beetles, leafhoppers, grasshoppers, stink bugs, and others (see the Insect Table for a listing of these species). Because Troublesome Sedge occurs in a wide variety of habitats (wetlands, prairies, & open woodlands), this sedge (and others) is a potential source of food to many vertebrate animals. Waterfowl, upland gamebirds, and many songbirds eat the seeds of sedges (see Bird Table). Other animals that feed on sedges include Chelydra serpentina (Snapping Turtle), Kinosternum subrubrum (Eastern Mud Turtle), Gray Squirrel and Fox Squirrel (seeds/seedheads), Black Bear (both foliage & seedheads), Common Mole (roots), and Prairie Vole (foliage, seeds). While sedge foliage is non-toxic to hoofed mammalian herbivores (deer, cattle, horses, etc.), it is not preferred as a source of forage.
Photographic Location: A seasonal wetland at Judge Webber Park in Urbana, Illinois.
Comments: Notwithstanding its strange name, this is an attractive sedge with tight bunches of slender leaves and prickly-appearing seedheads. It resembles several other Carex spp. in the Ovales section and can be difficult to identify. In general, Troublesome Sedge has the following set of key characteristics: 1) It has only 2-4 spikelets (rarely 5) that are clustered closely together, 2) these spikelets are nearly globoid and they have well-rounded bottoms, 3) the typical perigynium is about 4 mm. long and 2.02.5 mm. across, and 4) the leaf blades are less than 3.5 mm. across. Other similar sedges include Carex normalis, Carex cristatella, Carex brevior, and Carex festucacea. Two of these species, Carex normalis and Carex cristatella, have wider leaf blades (up to 6 mm. across) and more spikelets per inflorescence (about 4-12). The sedge Carex brevior also has more spikelets per inflorescence (about 4-8), slightly wider leaf blades (up to 4 mm. across), and slighter wider perigynia (2.53.5 mm. across). The remaining sedge, Carex festucacea, often has a similar number of spikelets per inflorescence, but they are less densely clustered together than the spikelets of Troublesome Sedge; also, the perigynia of Carex festucacea are a little shorter (typically about 3 mm. in length).