Bottlebrush Sedge
Carex comosa
Sedge family (Cyperaceae)

Description: This perennial sedge forms a large tuft of leaves and flowering culms about 2–3' tall. The erect to ascending culms are light green, sharply 3-angled, and glabrous. Alternate leaves occur along the entire length of the culm to the inflorescence. The widely spreading to ascending leaf blades are about 8-18" long and 6-17 mm. across; they are light to medium green and glabrous. The center of each blade is usually furrowed along its length. The sheaths are a little loose to firm; the outer 2 sides of each sheath are light green, veined, and glabrous, while the inner side is membranous. The ligules are longer than they are across; each short-membranous ligule has an upside-down V-shape.

Each fertile culm terminates in an inflorescence consisting of 2-6 pistillate spikelets, a terminal staminate spikelet, and their leafy bracts. The lowest bract is up to 16" long and 12 mm. across, while the upper bracts are smaller in size. Each pistillate spikelet is about 5-6 cm. long, 1.5 cm. across, and cylindrical in shape; it has a bristly appearance from the beaks and long teeth of the densely packed perigynia (bladder-like sacs). These perigynia are widely spreading. Each perigynium is about 5-7 mm. long, 1.5 mm. across, lanceoloid in shape, longitudinally veined, and glabrous; its bottom is wedge-shaped, while its beak has two spreading teeth (1.0–2.0 mm. long). The pistillate scales are usually a little shorter than the perigynia; they are lanceolate, membranous with central green veins, and awned. At the base of each pistillate spikelet, there is a slender stalk up to 1" long; the pistillate spikelet is held erect or it may nod slightly from its stalk. The terminal staminate spikelet is up to 7.5 cm. (3") long, very narrow, and brown; it has a short stiff stalk at its base up to 1 cm. long. The blooming period occurs from late spring to early summer. Mature achenes are 1.5–2.0 mm. and a little less across; they are ovoid-ellipsoid, bluntly 3-angled or a little flattened, and light brown. The root system is fibrous and short-rhizomatous.

Cultivation: Bottlebrush Sedge prefers full sun to light shade, wet conditions, and mucky or slightly sandy soil. It is one of the more ornamental sedges that can used in rain gardens.

Range & Habitat: The native Bottlebrush Sedge is occasional in NE Illinois, uncommon in central Illinois, and rare elsewhere (see Distribution Map). Habitats include swamps, bogs, seeps, margins of ponds and oxbow lakes, marshes, swales in damp meadows, and ditches. This sedge is often found in shallow water.

Faunal Associations: Many insects feed on wetland sedges (Carex spp.). This includes Stethophyma celata (Otte's Sedge Grasshopper), Stethophyma gracile (Graceful Sedge Grasshopper), and Stethophyma lineata (Striped Sedge Grasshopper). The caterpillars of the butterfly Satyrodes eurydice (Eyed Brown) and several skippers feed on the foliage. These skippers are Euphyes conspicua (Black Dash), Euphyes dion (Dion Skipper), Euphyes dukesi (Duke's Skipper), Euphyes vestris (Dun Skipper), Poanes massasoit (Mulberry Wing), and Polites mystic (Long Dash). As a group, skippers are important pollinators of many flowering plants. Other insects that feed on these sedges are the caterpillars of the moth Chortodes inquinata (Noctuid Moth sp.) and many other moths, several leaf beetles (Plateumaris spp. & others), the billbugs Sphenophorus costipennis and Sphenophorus callosus, the seedbugs Oedancala dorsalis and Cymus angustatus, several leafhoppers (Cosmotettix spp. & others), and many aphids (see Aphid Table). Among vertebrate animals, many wetland birds eat the seeds or seedheads. These include the American Coot, Wilson Snipe, several rails, many ducks, and the Swamp Sparrow. The Sedge Wren constructs its nest and hunts for insects in wetlands that are dominated by sedges.

Photographic Location: Border of a marshy pond at Weaver Park in Urbana, Illinois.

Comments: Bottlebrush Sedge is a member of a small group of wetland sedges that have bottlebrush-shaped pistillate spikelets. They are attractive in appearance, but require moist to wet conditions. Bottlebrush Sedge can be readily distinguished from similar sedges by the long spreading teeth of its perigynia (1.0–2.0 mm.); similar sedges have shorter teeth that remain appressed together. It also has perigynia that are less inflated than those of similar sedges. Another common name of Carex comosa is Bristly Sedge.