SafePlants

Illinois Flatsedge (Cyperus grayoides)

Cyperus grayoides, commonly known as Illinois flatsedge or Mohlenbrock's umbrella sedge, is a species of sedge native to the United States.

Considerations for Pets

• This plant produces tubers.
• The plant has culms, which can be up to 8" long.
• This plant has rhizomes.

Taxonomy and Nomenclature

• Scientific Name: Cyperus grayoides Mohlenbr.
• Family: Cyperaceae (Sedge Family)
• Taxonomic Rank: Species
• Synonyms: Mentions Cyperus grayi as a possible synonym.

Common Names

• Illinois Flatsedge
• Mohlenbrock's Umbrella Sedge
• Umbrella Sedge
• Midwestern Gray's Flatsedge
• Deep Sand Flatsedge

Distribution and Habitat

• Native to the United States, with specific mention of Illinois.
• Occurs along the entire eastern seaboard south to Louisiana.
• Found in ditches in the interior US (Illinois).

Morphological Characteristics

• Perennial graminoid plant.
• Summer annual flatsedge, with some varieties lasting 2-6".
• Can grow up to 10" tall as a summer annual.
• Culms are 3-angled, glabrous, and rather stout.
• Some leaves develop along the lower half.
• Has short rhizomes and bears moniliform tubers.
• Culms can be sprawling to erect and unbranched, up to 8" long, medium or olive green.

Ecological Role

• Mentioned in the context of Sandy longleaf pine savannah.

Related Species

• Cyperus esculentus (Chufa Flat-sedge)
• Cyperus filicinus (Fern Flatsedge)
• Cyperus diandrus (Umbrella Flat Sedge)
• Cyperus cephalanthus (Buttonbush Flatsedge)
• Cyperus strigosus (False Nutsedge, Strawcolored Flatsedge, Strawcolor Nutgrass)
• Cyperus lupulinus
• Cyperus alopecuroides (foxtail flatsedge)
• Cyperus hystricinus (bristly flatsedge)

Further Information

• Illinois Plant Information Network (ILPIN): Illinois Distribution
• Dave's Garden
• Illinois Natural History Survey
• Illinois State Archaeological Survey
• Illinois State Geological Survey
• Illinois Wildflowers: http://www.illinoiswildflowers.info/grasses/plants/straw_flsedge.htm