Star Sedge
Carex radiata
Sedge family (Cyperaceae)

Description: This perennial sedge often forms a dense tuft of leaves and culms, spanning about 1' tall and across. The slender culms are triangular in cross-section, light green, and hairless. Several alternate leaves occur along the lower one-third of each culm. The slender leaf blades are up to 12" long and 2 mm. across, light green, and hairless; they are ascending to widely spreading and slightly to moderately recurved. The tight sheaths are light green along the two outer surfaces and translucent along the inner surface; the mouth of each sheath is usually concave.

Most of the culms terminate in a floral spike about 1"–3" long, consisting of 3-8 spikelets. The spikelets are more widely spaced from each other toward the bottom of the spike than the apex. Each spikelet consists of a tight cluster of 1-9 perigynia; these perigynia are initially erect, but they later become slightly ascending, slightly descending, or widely spreading, forming a star-like cluster. Underneath the lower 2-3 spikelets, there are linear leafy bracts (up to 2" in length). Male florets, if present, are located above the female florets and their perigynia. Each mature perigynium is about 3 mm. long and 1.5 mm. across; it is ovoid-lanceoloid in shape, smooth across the surface, and somewhat flattened, tapering gradually to a small beak. The pistillate scales are about 2 mm. long, 1.5 mm. across, and ovate in shape; except for a central green vein, they are translucent. Initially, the perigynia are light green, but they later turn brown. Protruding from the beak of each perigynium, there is a pair of styles about 1 mm. long; these styles are either straight or slightly twisted. The short blooming period occurs during the late spring. The female florets are wind-pollinated. Each mature perigynium contains a single achene about 1.5 mm. long and 1.0 mm. across; it is ovoid and somewhat flattened. The root system is fibrous and short-rhizomatous. This sedge reproduces primarily by reseeding itself into new areas.

Cultivation: A favorable environment consists of dappled sunlight to medium shade, moist to mesic conditions, and a rich loamy soil with abundant organic matter.

Range & Habitat: The native Star Sedge is common throughout Illinois (see Distribution Map). Habitats include moist to mesic deciduous woodlands, edges of shaded seeps, and slopes of shaded ravines. Star Sedge is found in both undisturbed and slightly degraded woodlands.

Faunal Associations: The floral-faunal relationships of Star Sedge are similar to other sedges, although these are strongly influenced by this sedge's fidelity to woodland habitats. It does not provide much cover for vertebrate wildlife, but the seeds are eaten by various songbirds and upland gamebirds that prefer wooded habitats. Many species of insects feed on this and other sedges; such insects are sources of food to many birds and mammals.

Photographic Location: A mesic deciduous woodland (Busey Woods) at Urbana, Illinois. The sedge is blooming in the upper photograph, however the perigynia of the inflorescence will not assume their full size until later in the season.

Comments: Because of the dense tuft of slender leaves and star-like clusters of the inflorescence, this medium-small sedge is rather ornamental. Star Sedge is very similar in appearance to another common species, Carex rosea (Curly-Style Star Sedge), which is found in the same woodland habitats. This sedge differs from Star Sedge by its strongly recurved styles and its slightly wider leaf blades (up to 3 mm. across). Another similar species, Carex socialis (Colonial Sedge), differs primarily by its long rhizomes and loose tufts of leaves. However, this latter sedge is restricted to the southern tip of Illinois.