Yellow nut sedge, Cyperus esculentus

Life Cycle



Reproducing by seed and by underground stems (rhizomes)and tubers.


Stems 10 - 90 cm high, distinctly triangular in cross-section and usually less than 1 cm thick.


Leaves numerous at the base of the plant and sparse up the stem except for a cluster of usually 3 to 5 at the base of the inflorescence; leaf arrangement alternate and 3-ranked, that is, the leaves pointing outwards in 3 directions from the stem; leaf sheath closed forming a 3-sided cylinder around the stem; leaf blades grass-like, long (often longer than the stem) and narrow, 3 - 10 mm wide, flat or somewhat folded, light green to yellowish-green; no ligule and no auricles.

Flowers and Fruit

Inflorescence an umbrella-like cluster of yellowish to brownish branches at the tip of the stem; spikelets (containing the seeds) very small and closely arranged along slender secondary branches (d). Flowers from July to August.

Roots and Underground Structures

The underground system is a mixture of long, thin, wiry rhizomes 5 - 20 cm long or longer, and a mass of fine fibrous roots. Rhizomes are light brown to whitish, have nodes (a) and internodes (b) with short, dark brown, dry scale-like sheaths; tubers (c) produced at the tips of some rhizomes, dark brown, somewhat spindled-shaped, 5 - 20 mm long and usually narrower, edible with a taste somewhat suggestive of almonds.


Yellow nut sedge is native on moist, sandy soils throughout much of North America. It is common in Southern Ontario, frequently infesting moist areas of cultivated fields, pastures, roadsides, gardens and lawns.


Corn yield loss (%)*: 2 % at 1 plant/m2 7 % at 5 plant/m2 Soybean yield loss (%)*: 2 % at 1 plant/m2 7 % at 5 plant/m2 *assumes that the weed has emerged with the crop and has been left uncontrolled all season.

Distinguishing Features

It is easily distinguished from all grasses by its triangular stem together with slender, tuber-bearing (c) rhizomes. Several other species of nut sedge also occur in Ontario but this is the most troublesome one and the most likely to occur in cultivated land.


Yellow nutsedge is not known to be toxic. The nutlets are edible.

Human Health Issues

Yellow nutsedge is not a known allergen.

Forage Quality

No information exists at this time.


The old weed science 101 saying "If it has edges, it’s a sedges" hold strue. Touch the stem of yellow nutsedge and you can fell a distinct triangle-shape stem, the only prominent "grass-like" weed with this unique chracteristic.

Species Benefits

The nutlets can be eaten raw, boiled, dried and ground into flour or roasted to a dark brown and ground into coffee. From: Peterson, LA, 1977, A Field Guide to Edible Wild Plants of Eastern and Central North America, Houghton Mifflin Company, New York.

Power Ranking Corn

Power Ranking

↑ 9


Power Ranking Soybeans

Power Ranking

↑ 15


Biological Control

Currently none available for this weed. For the latest research on biological weed control:

Biopesticide Control

Currently none available for this weed.

Herbicide Resistance

No documented cases of herbicide resistance to date. Various different biotypes exist, with each exhibiting different levels of herbicide sensitivity. For more information on weed resistance:

Figure #1.

Drawing of Yellow nutsedge

Figure #2.

Leaf sheath: Closed forming a 3-sided, trinagle shape around the stem.

Figure #3.

Leaf blade: Hairless with a prominent mid rib and numerous leaves coming out at the base of the plant.

Figure #4.

Rhizomes: Light brown to whitish.

Figure #5.

Tubers: Located at the tip of the rhizomes. Mature tubers are dark brown, newly formed tubers start out white.

Figure #6.

Seed head.