Cyperus esculentus L.

Keys to Identification

• Yellow nutsedge can be identified by its stout triangular stem
• 3-ranked, grass-like leaves
• Yellow nutsedge also has dark, unevenly globe-shape, almond tasting tubers at the ends of slender rhizomes

This information courtesy of the Colorado Natural Areas Program

Family

Sedge (Cyperaceae)

Other Names

Chufa, chufa flatsedge, nut-grass, galingale.

USDA Code

CYES

Legal Status

Colorado Noxious Weed List B

Identification

Lifecycle

Perennial

Growth form

Grass-like

Flower

Flowers are yellowish-brown. The entire cluster of flat spikelets have by 3-9 leaflike bracts below.

Seeds/Fruit

Seeds are yellowish, triangular, and oblong.

Leaves

Grass-like leaves originate from the base of each stem, while long leaf-like bracts radiate out from a common point just below the umbrella-like flower cluster.

Stems

Plants range from 6-30 in tall, with 3-ranked leaves, and 3-angled pithy stems.

Roots

Tubers (at the tips of rhizomes) are dark, unevenly globe-shaped, and edible, tasting something like almonds.

Seedling

Stems are triangular in cross section. Leaves are smooth, hairless and deeply keeled. The plant is yellowish to pale green (Carey et al. 1993).

Other

The leaves have a sweet scent.

Similar Species

Exotics

None known.

Natives

None known.

Impacts

Agricultural

The nutsedges are the most difficult weeds to control in cultivated fields, often forming a solid cover over large areas in sorghum and alfalfa pastures, flood plains, dams, ditches, and along streams and roadsides (Parker 1972). Yellow nutsedge can also be troublesome in crops like potatoes, beans, and corn (Whitson et al. 1996). It reduces crop yield and quality by competing for light, water, and nutrients, and by interfering with pesticide applications and harvest operations (Ackley et al. 1996).

Ecological

Yellow nutsedge is a noxious weed of wet soil. Infestations often start in wet areas, and then spread outward.

Habitat and Distribution

General requirements

Yellow nutsedge is found in many soil types, but is common on well-drained, sandy soils or damp to wet sites. It can commonly be found in irrigated crops, along streams, around lakes and ponds, wet fields, and wet prairies.

Distribution

Found in cultivated agricultural lands throughout North America.

Historical

Yellow nutsedge was probably introduced from Europe. The tubers are edible by humans and wildlife. Some people consider the tuber a delicacy.

Biology/Ecology

Life cycle

Plants are yellowish-green. Flowers appear one per scale, with many scales per spikelet (USDA 1997). Flowering occurs from July to October.

Mode of reproduction

Yellow nutsedge reproduces by rhizomes, tubers, and sometimes seed. Rhizomes radiate from the main plant, ending in bulbs or tubers, which may produce new plants.

Seed production

No information available.

Seed bank

No information available.

Dispersal

No information available.

References

Ackley, J.A., H.P. Wilson, and T.E. Hines. 1996. Yellow nutsedge (Cyperus esculentus) control post with acetolactate synthase-inhibiting herbicides. Weed Technology 10:576-580.

Carey, J. Boyd, James J. Kells, and Karen A. Renner. 1993. Common Weed Seedlings of Michigan. Department of Crop and Soil Sciences Michigan State University Extension. Bulletin E-1363. Internet 10/27/99. Available: http://www.msue.msu.edu/msue/iac/e1363/e1363.htm

Parker, K.F. 1972. Yellow nutsedge-Cyperus esculentus L. An illustrated guide to Arizona weeds. University of Arizona Press, Tucson. Available: http://www.uapress.arizona.edu/online.bks/weeds/yellonut.htm

U.S. Department of Agriculture. No date. Midwestern wetland flora: Field office guide to plant species. USDA. Soil Conservation Service, Midwest National Technical Center, Lincoln, Nebraska. Jamestown, ND: Northern Prairie Wildlife Research Center Home Page. http://www.npwrc.usgs.gov/resource/othrdata/plntguid/plntguid.htm (Version 16JUL97).

Whitson, T.D.(ed.), L.C. Burrill, S.A. Dewey, D.W. Cudney, B.E. Nelson, R.D. Lee, R. Parker. 1996. Yellow nutsedge. Weeds of the West. Western Society of Weed Science, in cooperation with the Western United States Land Grant Universities Cooperative Extension Services, Newark CA. pg. 298.