Pennsylvania Sedge
Carex pensylvanica
Sedge family (Cyperaceae)

Description: This perennial sedge forms small loose tufts of leafy culms about –1' tall; both fertile and sterile shoots occur. The culms are unbranched, light green, sharply 3-angled, and glabrous; they have alternate leaves. The leaf blades are 1-3 mm. across; they are usually shorter than the fertile culms, but longer than the sterile culms. The leaf blades are light green, glabrous, and furrowed along their midveins; they are ascending to widely spreading and arching. The leaf sheaths are light green, longitudinally veined, and glabrous. Each fertile culm terminates in an inflorescence consisting of a terminal staminate spikelet, 2-3 pistillate spikelets, and their bracts. The narrow staminate spikelet is 1.0–2.5 cm. long on a short peduncle. The staminate scales of this spikelet are 3.5–5.0 mm. long, 1.5 mm. across, and lanceolate or elliptic in shape; they are dark purple during the blooming period, often with green midveins and membranous margins. The large anthers of the staminate florets are cream-colored and linear in shape; they become dull light brown with age. The sessile pistillate spikelets are much smaller in size than the staminate spikelet; they are adjacent to each other or slightly separated. Each pistillate spikelet has about 4-12 perigynia and their scales.

The perigynia are 2.5–3.0 mm. long and 1.5 mm. across; they have ovoid-globoid bodies with short stout beaks and stipe-like bases that are also short and stout. Immature perigynia are light green and either glabrous or finely short-pubescent. The pistillate scales are about the same length as the perigynia; they are ovate in shape, dark purple, and membranous along their margins. Each pistillate floret has 3 styles that are slender and white. At the base of the lowest pistillate spikelet, there is a green to purple leafy bract that is as long or a little longer than the spikelet (up to 1 cm. in length). Other bracts of the inflorescence are smaller in size and often scale-like. The blooming period occurs from mid- to late spring, lasting about 1-2 weeks. The florets are cross-pollinated by the wind. The achenes are about 1.5–2.0 mm. long, globoid-obovoid in shape, and slightly 3-angled. The root system produces long stolons than run along the surface of the soil (underneath fallen leaves and other debris). Loose clonal colonies are often formed from these stolons.

Cultivation: Pennsylvania Sedge prefers partial or dappled sunlight and mesic to dry conditions with good drainage. A sandy loam or loose loam with abundant organic matter is preferred; this sedge also adapts to thin rocky soil if there is a layer of loam and decaying organic matter on top.

Range & Habitat: The native Pennsylvania Sedge is occasional to locally common in most areas of Illinois; it is least common in south-central Illinois (see Distribution Map). Habitats include upland woodlands, thinly wooded bluffs, wooded slopes, sandy savannas, rocky or sandy openings in wooded areas, hill prairies, and upland prairies. This sedge is often found in dry woodland areas where oak trees (Quercus spp.) are present.

Faunal Associations: Insects that are known to feed on Pennsylvania Sedge include the leafhopper Cosmotettix delector, the aphid Iziphya albipes, and such grasshoppers as Arphia pseudonietana (Red-winged Grasshopper), Orphuella speciosa (Pasture Grasshopper), and Trachyrhachys kiowa (Kiowa Grasshopper). Other insects that feed on sedges (Carex spp.) include larvae of the grass-miner moths Elachista argentosa and Elachista madarella, Chloealtis abdominalis (Thomas' Broad-winged Grasshopper), and such aphids as Iziphya flabella, Carolinaia caricis, and Vesiculaphis caricis (Panzer et al., 2006; Wyoming Agr. Exp. Sta., 1994; Vickery & Kevan, 1985; Microleps website, 2010; Blackman & Eastop, 2013). Various birds eat the seeds of sedges in habitats that are favored by Pennsylvania Sedge; these species include the Greater Prairie Chicken, Wild Turkey, immature Ruffed Grouse, Eastern Towhee, and various sparrows (Martin et al., 1951/1961). Sedges in such habitats are a source of food to the Prairie Vole as well.

Photographic Location: Wooded slopes in Vermilion County, Illinois.

Comments: This is one of the first sedges to bloom during the spring. Pennsylvania Sedge (Carex pensylvanica) is very similar to Carex lucorum and Sun Sedge (Carex heliophila); these latter two species are sometimes considered different varieties of Pennsylvania Sedge (e.g., Carex pensylvanica distans and Carex pensylvanica digyna respectively). Compared to Pennsylvania Sedge, these species/varieties have longer perigynia (3.0–4.0 mm. in length). The perigyneal beaks of Carex lucorum are more slender and long than those of Pennsylvania Sedge, while Sun Sedge has leaf blades that are more stiff and revolute (rolled). Two other species that are similar in appearance, Carex communis and Carex albicans, lack the long stolons of Pennsylvania Sedge. Most of these species prefer similar habitats to Pennsylvania Sedge, although Sun Sedge is more common in the open prairies of the Great Plains states.