Sedge family (Cyperaceae)
Description: This native perennial plant is about 1½–3' tall, consisting of tight tufts of leaves and one or more flowering culms. The erect to ascending culms are light green to green, 3-angled, hairless, and rather spongy toward the base, becoming more slender at the apex where the inflorescence occurs. The alternate leaves are produced from infertile shoots and the flowering culms; they are up to 2' long and ½" across, light green to green, hairless, and linear in shape. The leaves arch outward and downward, forming pseudo-rosettes; the larger leaves are conspicuously indented along their central veins. At the apex of each culm, there is an inflorescence consisting of a terminal staminate spikelet (less often 2-3 staminate spikelets) and 2-7 pistillate spikelets. The staminate spikelet is up to 4" long, light to dark brown, and somewhat flattened; it can be nearly sessile, short-stalked, or long stalked. Each pistillate spikelet is up to 3½" long and 1¼" across; it is oblongoid-cylindrical and densely crowded with the inflated perigynia of the pistillate flowers. Initially, the pistillate spikelets are light green to green, but they become yellowish brown with maturity; they usually occur in a loose cluster on short slender peduncles. Each perigynium is up to 15 mm. (2/3") long and 6 mm. (¼") across; it is lanceolate-ovoid in shape, tapering to a long conical beak. There are several longitudinal veins along the outer surface of the perigynium. The pistillate scales are smaller in size than the perigynia; each of these scales is lanceolate, tapering gradually into an awned tip. Young pistillate scales have green central veins and translucent margins; they later become light brown. The blooming period occurs from late spring to mid-summer (rarely later) and lasts about 2 weeks. At this time, each pistillate flower has 3 curly white stigmas that are exerted from the beak of its perigynium. The achenes are about 3 mm. long and 3 mm. across; they are rhomboid-hexaploid and sharply angular (looking like light green diamonds); sometimes they are slightly knobby where their edges meet, and their sides are often slightly concave. At the apex of each achene, there is a persistent style that is coiled or curved near the base; this style is light green and longer than the achene. The root system consists of rhizomes and a dense tuft of fibrous roots. This sedge often forms vegetative clumps of plants from its rhizomes.
Cultivation: The preference is light shade to full sun, wet to consistently moist conditions, and a mucky soil. Occasional flooding is tolerated, although not for long periods of time. The leaves become a lighter shade of green in bright sunlight.
Range & Habitat: Hop-like Sedge occurs in widely scattered locations throughout Illinois (see Distribution Map); it is fairly uncommon. Habitats include wet to moist areas of floodplain woodlands, swamps, soggy meadows along streams, degraded marshes, and roadside ditches. This is primarily a wetland species that often occurs in wooded areas that are partially shaded. It also occurs in degraded wetlands in full sun, often near stands of cattails (Typha spp.) or Reed Canary Grass (Phalaris arundinacea). Hop-like Sedge can be used successfully in wetland restorations.
Faunal Associations: The flowers are wind-pollinated and do not attract many insects. The caterpillars of various butterflies, skippers, and moths feed on Carex spp. (usually the foliage). See the Lepidoptera Table for a listing of these species. Other insects feeding on Carex spp. include Stethophyma lineata (Striped Sedge Grasshopper), Stethophyma celata (Otte's Sedge Grasshopper), and various leafhoppers (Cosmotettix spp. & others). The seeds of Carex spp. are eaten by various upland gamebirds, waterfowl, and songbirds (see the Bird Table for a listing of these species).
Photographic Location: A marsh at the Prairie Ridge State Natural Area in Jasper County, Illinois. This marsh was created from a farm field.
Comments: This is one of the more attractive sedges in Illinois – the large pistillate spikelets have a striking appearance, resembling a spiked-club or similar weapon of medieval warfare. Hop-like Sedge closely resembles Carex lupulina (Hop Sedge), and distinguishing these two species can be rather difficult. The most reliable method of identification involves an examination of their achenes: Hop-like Sedge has rhomboid-hexaploid achenes that are as broad as they are long (diamond-shaped), while the achenes of Hop Sedge are longer than they are broad (because they are somewhat flattened). The common names of these species refer to the superficial resemblance of their pistillate spikelets to the fruits of Humulus lupulus (Hop Vine). Another common name of Carex lupuliformis is False Hop Sedge.