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Yellow nutsedge Cyperus esculentus L. |
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Keys to Identification:
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This information courtesy of the Colorado Natural Areas Program Family: Cyperaceae (Sedge) Other Names: chufa, chufa flatsedge, nut-grass, galingale USDA Code: CYES Legal Status: Colorado Noxious Weed List B Identification Lifecycle: perennial Growth form: graminoid Flower: Flowers are yellowish-brown in appearance. The entire cluster of flat spikelets is subtended by 3-9 leaflike bracts. 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 inches 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. Human: No information available. 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 in color. 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. Integrated Management Summary Mechanical and/or chemical control methods can be used to eliminate seed production and deplete the nutrient reserves in the rhizomatous root system. Land use practices which maintain a healthy cover of perennial plants will help prevent the spread of yellow nutsedge. References
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