Ontario Weeds: Yellow nutsedge

Table of Contents

1. Name
2. Other Names
3. Family
4. General Description
   • Photos and Pictures
5. Stems and Roots
6. Flowers and Fruit
7. Habitat
8. For more information...

Name: Yellow nut sedge, Cyperus esculentus L.,

Other Names: CYPES, souchet comestible, Chufa, Earth almond, Ground almond, Northern nut-grass, Nut-grass, Rushnut, Yellow nut-grass, amande de terre, souchet rampant.

Family: Sedge Family (Cyperaceae)

General Description: Perennial, reproducing by seed and by underground stems (rhizomes) and tubers. It is easily distinguished from all grasses by its triangular stem together with slender, tuber-bearing 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.

Photos and Pictures

Stems & Roots: The underground system is a mixture of long, thin, wiry rhizomes 5 - 20 cm (2 - 8 in.) long or longer, and a mass of fine fibrous roots. Rhizomes are light brown to whitish, have nodes and internodes with short, dark brown, dry scale-like sheaths; tubers produced at the tips of some rhizomes, dark brown, somewhat spindled-shaped, 5 - 20 mm (1/5 - 4/5 in.) long and usually narrower, edible with a taste somewhat suggestive of almonds; stems 10 - 90 cm (4 in. - 3 ft) high, distinctly triangular in cross-section and usually less than 1 cm (2/5 in.) 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 (1/8 - 2/5 in.) wide, flat or somewhat folded, light green to yellowish-green; no ligule and no auricles.

Flowers & 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. Flowers from July to August.

Habitat: 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.

For more information...

... on weed identification, order OMAFRA Publication 505: Ontario Weeds

... on weed control, order OMAFRA Publication 75: Guide To Weed Control

...on weeds in field crops, contact Mike Cowbrough (mike.cowbrough@ontario.ca), Weed Management Specialist (Field Crops), OMAFRA
...on weeds in horticultural crops, contact Kristen Callow (kristen.callow@ontario.ca), Weed Management Specialist (Hort Crops), OMAFRA

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