Cyperus esculentus
yellow nutsedge
Uncertain; cosmopolitan, possibly native to parts of North America, Europe, and AfricaOverview
Cyperus esculentus is a rhizomatous perennial sedge in the family Cyperaceae reaching 8–30 inches (20–75 cm) tall with a 6–18 inch (15–45 cm) spread. Stems (culms) are erect, triangular in cross-section (a key sedge character), smooth, and solid. Leaves are basal and cauline, grass-like, 0.15–0.35 inch (4–9 mm) wide, V-shaped in cross-section with a prominent midrib, glossy, and lighter yellow-green than most grasses. The inflorescence is a terminal umbel-like cluster of golden-yellow to brown spikelets subtended by 3–6 leaf-like bracts of unequal length. The primary means of reproduction and spread is via underground tubers (nutlets), 0.3–0.6 inch (8–15 mm) in diameter, produced at the tips of slender rhizomes 2–14 inches (5–35 cm) long. A single plant produces 100–700 tubers per growing season. Tubers remain viable in soil for 3–10 years and survive freezing, drying, and passage through the digestive tracts of birds. The tuber-based persistence makes this species one of the most difficult-to-manage weeds in irrigated agriculture, turf, and nursery production worldwide. Ranked among the top 10 worst weeds globally.
Native Range
Native range uncertain due to ancient cosmopolitan distribution; considered native to parts of North America, southern Europe, and Africa. Found in moist to wet soils in cultivated fields, irrigated cropland, turf, nurseries, ditches, and wet meadows from sea level to approximately 6,500 feet (2,000 m). Present across all 50 U.S. states and most temperate and tropical regions worldwide.Suggested Uses
Used in weed identification training for teaching the sedge-grass-rush distinction (sedges have edges, grasses have nodes, rushes are round). Studied in weed biology as a model for tuber-based persistence. Tubers are edible and cultivated commercially in Spain as chufa for production of horchata de chufa (tiger nut milk). Tubers consumed by waterfowl and wild turkeys.How to Identify
Appearance
Size & Dimensions
Height8" - 2'6"
Width/Spread6" - 1'6"
Bloom Information
Flowers from July through October. Spikelets mature over 3–4 weeks. Wind-pollinated. Seed viability is low in temperate climates; reproduction is overwhelmingly by tubers. In the Pacific Northwest, tuber production begins in midsummer and peaks in September through October as day length shortens.Detailed Descriptions
Flower Description
Yellow to golden brownFoliage Description
Light to yellow-green, glossy, grass-like, V-shaped in cross-section with a prominent midribGrowing Conditions
Sun Requirements
Requires 6-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight