purple nutsedge
Cyperus rotundus L.


Cyperus rotundus is a perennial which rarely reproduces by seed but extensively reproduces by rhizomes which initially are white and fleshy with scale leaves, later becoming ligneous or "wiry."
The leaves are three-ranked, shiny, dark green, and corrugated in cross section. They are 0.24-0.39 in. (6-10 mm) wide and 3.9-13.8 in. (10-35 cm) long. The rachis, which grows through the center of the leaf bundle, is erect, simple, smooth, triangular in cross section, and 3.9-23.6 in. (10-60 cm) long.
Near the ends are clusters of narrow spikelets, 0.3-1 in. (0.8-2.5 cm) long and 0.07 in. (2 mm) wide, 10- to 40-flowered, acute and compressed with a red, reddish-brown, or purplish-brown color.
Fruits are 3 angled achene.
Ecological Threat
Infests crop production areas in tropical and temperate climates, causing large losses in crop yields.

Selected Images


EDDMapS Distribution

EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit www.eddmaps.org

State Regulated List

State Regulated List - This map identifies those states that list this species on their regulated list. For more information, visit Invasive.org

State Regulated List
   No Data for this state
   Troublesome or Common weed in one or more crops

Most Troublesome / Most Common Agricultural Weed List
This map identifies those states that consider this species either most troublesome or most common in at least one commodity. For more information, visit the MTMC project page.

Taxonomic Rank

Kingdom: Plantae
Phylum: Magnoliophyta
Class: Liliopsida
Subclass: Commelinidae
Order: Cyperales
Family: Cyperaceae
Genus: Cyperus
Subject: Cyperus rotundus L.

Synonyms and Other Names

Other Common Names:
nutgrass, chaguan humatag, cocograss, kili'o'opu, pakopako, purple nutsedge


Plants - Grass or Grasslike