bristly sedge

(Carex comosa)

Conservation Status
bristly sedge
Photo by Luciearl
  IUCN Red List

LC - Least Concern


NNR - Unranked

SNR - Unranked


not listed

Wetland Indicator Status
  Great Plains

OBL - Obligate wetland


OBL - Obligate wetland

  Northcentral & Northeast

OBL - Obligate wetland


Bristly sedge is a large, broad-leaved, true sedge. It occurs in the eastern United States from Maine to Florida west to Minnesota and Louisiana, in the west from Washington to California, in adjacent Canadian provinces, and in Mexico. It is found in swamps, marshes, wet thickets, and depressions in wet meadows; on the shores of ponds and lakes; and on floating mats of vegetation. It is often emergent in shallow water, near or even well away from the shore. It sometimes roots on floating logs.

Bristly sedge is an erect, perennial sedge that rises in a loose or dense clump from a short, horizontal, underground stem (rhizome) and fibrous roots.

Both sterile (vegetative) and fertile (flowering) stems (culms) are produced, more of the former than the latter. The vegetative culms are well-developed and have several leaves. Flowering culms are 20 to 47 (50 to 120 cm) tall. They are erect, unbranched, leafy, and three-sided with sharp edges. They are hairless, rough to the touch near the top, and tinged brownish at the base.

Stem leaves are alternate and widely spreading to ascending. They appear along the entire length of the culm below the inflorescence. All of the leaves, even at the base, have well-developed blades. The leaf blade is hairless, light green to medium green, 8 to 20 (20 to 50 cm) long, and 316 to (5 to 16 mm) wide. It is usually W-shaped in cross section, sometimes flat. The sheath is hairless, deeply concave at the tip, light green and veined on the outer side, papery (membranous) on the inner side. The sheath of the lowermost leaves is pale brown at the base. The sheath does not break into horizontal ladder-like fibers as it ages, and there is no red or purple coloration at the base. The sheaths of the previous season persist and are noticeable at the base of the plant. The ligule is V-shaped and longer than wide.

The inflorescence is a 1½ to 13¾ (4 to 35 cm) long, loosely spaced arrangement of spikes. There is a single male (staminate) spike at the tip of the stem and 2 to 6 female (pistillate) spikes near the top of the stem. The inflorescence is subtended by a single, 6 to 33½ (15 to 85 cm) long, inflorescence leaf (bract). The bract is much longer than the inflorescence.

The staminate spike is cylindrical and 1 to 3 (25 to 80 mm) long. It is held erect on a slender stalk (peduncle) that is up to (10 mm) long. Each male flower is subtended by a single modified leaf (scale). The staminate scale is lance-shaped to linear, to (4 to 9 mm) long, and tapered to a rough (scabrous), bristle-like tip (awn). It is reddish-brown and has a green or straw-colored midrib.

The pistillate spikes are cylindrical, to 3 (15 to 75 mm) long, and ½ to ¾ (12 to 18 mm) wide. They are on up to 1 long or longer peduncles. The upper spikes are spreading, the lower ones drooping. Each spike has numerous fruit capsules (achenes), and each achene has a sac-like covering (perigynium). At the base of each perigynia is a single scale. The pistillate scale is lance-shaped, to ½ (2.8 to 12 mm) long, 164 to 132 (0.4 to 1.0 mm) wide, and narrowed with concave sides (acuminate) toward the tip. It is shorter than the perigynium. The tip tapers to a long scabrous awn.

The perigynia are crowded and are spreading to bent backwards (reflexed) when mature. Each perigynium is narrowly egg-shaped. leathery, 316 to (4.8 to 8.7 mm) long, and 132 to 116(1.1 to 1.8 mm) wide. It entirely and tightly envelopes the achene at maturity. It is abruptly contracted into a long beak at the tip. It has 14 to 22 distinct, closely-spaced veins that converge about half way up the beak. The beak is tube-shaped, 116to (2 to 4 mm) long, and has two papery teeth at the tip. The teeth are 132to (2 to 3 mm) long and are distinctly curved outward.

The achene is dry, pale brown, 116 (1.7 to 2.0 mm) long, and triangular in cross section. It matures in late June to mid-September.




20 to 47 (50 to 120 cm)


Similar Species


Swamps, marshes, wet thickets, depressions in wet meadows, shores of ponds and lakes, floating mats of vegetation, and floating logs. Often emergent in shallow water.



  April to June  



Late June to mid-September


Pests and Diseases






Distribution Map



2, 3, 4, 5, 7, 24, 28, 29, 30, 84.









  Kingdom Plantae (green algae and land plants)  
  Subkingdom Viridiplantae (green plants)  
  Infrakingdom Streptophyta (land plants and green algae)  
  Superdivision Embryophyta (land plants)  
  Division Tracheophyta (vascular plants)  
  Subdivision Spermatophytina (seed plants)  
  Class Liliopsida (monocots)  


Poales (grasses, sedges, cattails, and allies)  


Cyperaceae (sedges)  
  Subfamily Cyperoideae  
  Tribe Cariceae  


Carex (true sedges)  
  Subgenus Carex  
  Section Vesicariae  





Common Names


bottle-brush sedge

bristly sedge

longhair sedge











A dry, one-chambered, single-seeded seed capsule, formed from a single carpel, with the seed attached to the membranous outer layer (wall) only by the seed stalk; the wall, formed entirely from the wall of the superior ovary, does not split open at maturity, but relies on decay or predation to release the contents.



Growing upward at an angle or curving upward from the base.



A stiff, bristle-like appendage at the tip of the glume, lemma, or palea of grass florets.



Modified leaf at the base of a flower stalk, flower cluster, or inflorescence.



The hollow or pithy stem of a grass, sedge, or rush.



In grasses and sedges, a membranous appendage at the junction of the leaf and the leaf sheath, sometimes no more than a fringe of hairs. In flowering plants, the flat, strap-shaped, petal-like portion of the corolla of a ray floret.



In angiosperms, the stalk of a single flower or a flower cluster; in club mosses, the stalk of a strobilus or a group of strobili.



In Carex and other closely related sedges, a sac-like structure that surrounds the pistillate flower and later encloses the achene. Plural: perigynia.



Referring to a flower that has a female reproductive organ (pistil) but does not have male reproductive organs (stamens).



A horizontal, usually underground stem. It serves as a reproductive structure, producing roots below and shoots above at the nodes.



On plants, a small, usually flat and thin, modified leaf resembling the scale of a fish. In sedges, a dry, reduced bract at the base of the perianth. On animals, a small rigid plate growing out of an animal’s skin to provide protection. On butterflies and moths, a plate on the surface of the wing providing coloration.



The lower part of the leaf that surrounds the stem.



Extending nearly horizontal.



Referring to a flower that has a male reproductive organs (stamens) but does not have a female reproductive organ (pistil).

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Growing on shore of Pine Song Lake

    bristly sedge   bristly sedge  








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Location: Fairview Twp, Cass County

Growing on shore of Pine Song Lake

bristly sedge  




Created: 8/24/2021

Last Updated:

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