Cyperus esculentus (Yellow Nutsedge)
Also known as: | Chufa Nutsedge, Earth Almond, Tiger Nut |
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Genus: | Cyperus |
Family: | Cyperaceae (Sedge) |
Life cycle: | perennial |
Origin: | Europe, Africa |
Status: |
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Habitat: | part shade, sun; moist, disturbed soil; cultivated fields, gardens, ditches, shores, banks, marshes |
Fruiting season: | August - October |
Plant height: | 6 to 24 inches |
Wetland Indicator Status: | GP: FACW MW: FACW NCNE: FACW |
MN county distribution (click map to enlarge): | |
National distribution (click map to enlarge): |
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Detailed Information
Flower:
Several to numerous clusters ¾ to 1+ inch long at the tip of the stem, each cluster oval to cylindric and loosely arranged with 10 to 20 spikelets (flower clusters), the spikelets arranged bottle-brush fashion on all sides of the cluster stalk, widely spreading to ascending. The 4 to 10 auxiliary clusters have stalks ¾ to 5 inches long, with 1 to 3+ clusters at the tip of a stalk. At the base of the group of clusters are 3 to 6 leaf-like bracts of varying lengths, V-shaped in cross-section, 2 to 12 inches long, all mostly ascending.
Spikelets are flattened, linear-oblong in outline, 15 to 20mm (½ to ¾ inch) long, with 6 to 34 florets, each subtended by a scale. Florets have 3 stamens and a 3-parted style. Scales are 1.8 to 2.7mm long, initially green turning straw-colored to golden or dark brown, lance to egg-shaped usually widest at the middle, with 3 to 5 ribs on each side and a green or brown midrib that is pointed at the tip. The scales are arranged on opposite sides of the central spikelet stalk (rachilla), overlapping and appressed to ascending. A narrow, papery wing runs along each side of the rachilla internode from the lower edge of the floral scale to the next scale below.
Leaves and stems:
Leaves are basal and alternate with 3 to 10 stem leaves near the base, bright yellowish-green, flat to V-shaped in cross-section, 2 to 6.5mm wide, 8 to 30 inches long, the longest leaves usually longer than the stem. Basal sheaths are brown to reddish-brown. Stems are single or multiple from the base, erect to ascending, fairly stout, 3-sided with sharp angles, and smooth. Plants may form loose clumps, form colonies from stolons and scaly rhizomes, and propagate vegetatively from small, hard tubers that develop at rhizome tips.
Fruit:
The floral scales and rachilla both persist at maturity. Achenes are 1.1 to 1.5mm long, brown when mature, 3-sided, generally elliptic in outline, slightly tapered to the base with a short stalk-like appendage (stipe), and more rounded at the tip. Achenes are often poorly developed and don't reach maturity.
Notes:
Cyperus esculentus is a common garden weed and agricultural pest with a gobal distribution, though in parts of the world it is cultivated for its edible tubers. It is very difficult to control once established, since it is resistant to most chemical treatments and mechanical or manual methods of control do not typically eliminate all the abundant tubers from which it regenerates. While the tubers and bright yellow-green foliage are distinctive characteristics, the bottle-brush like clusters are similar to other Cyperus species, notably Cyperus odoratus, Cyperus engelmannii, Cyperus strigosus and Cyperus erythrorhizos, none of which produce tubers. In addition, C. odoratus and C. engelmannii have spikelets that break apart between the florets, C. strigosus floral scales are much larger, 3 to 6mm long, and C. erythrorhizos has smaller scales, only 1 to 1.5mm long, that are typically more densely packed in slender cylindrical clusters and are darker reddish-brown.
While some references treat Cyperus esculentus as native to North America, it is not considered native in Minnesota. One recent study suggests it originated in Africa and migrated to the New World in pre-Columbian times via ocean currents, since the seeds, tubers, stolons and rhizomes can all float, and this method of long distance dispersal has been documented for other species. Here it morphed into new genotypes, adapted to cooler temperatures, and developed the invasive tendencies it is known to have today. There are currently 4 recognized varieties, distinguished by arrangement of spikelets, shape of floral scales, and size of anthers and styles: var. esculentus is considered the Old World species from which cultivated crops originated, vars heermannii and macrostachyus have limited ranges in the southern US into Central America, and var. leptostachyus, common across North America and considered invasive, described above.
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More photos
- Cyperus esculentus plant
- Cyperus esculentus plants
- Cyperus esculentus plants
- Cyperus esculentus plants
- Cyperus esculentus plants
- yellow-green foliage stands out
- spikelets are loosely arranged
- close-up of spikelet cluster
- tubers form on roots
Photos by K. Chayka taken in Ramsey County. Photos courtesy Peter M. Dziuk taken in Houston and Ramsey counties.
Comments
Have you seen this plant in Minnesota, or have any other comments about it?
on: 2017-08-03 19:00:38
Bought some bird/bees seed mix from Menards for $0.50 and seeded a small piece of garden with this mix. This plant was mixed in with the seeds. I will be removing the plant. This site is helpful as the seed mix didn't indicate each specific species.
on: 2018-07-24 14:27:27
I just identified this plant by County Road 6 and Fernbrook. It was growing along the walkway along Fernbrook, the Street. Just a few plants along the chain-link fence.
on: 2019-06-06 11:54:25
This plant grows like crazy along the south side of our house. I carefully pulled up every single plant last summer/fall, getting all of the "nuts" I possibly could, and this year they're still coming up in huge numbers. Some from last year released seeds before I realized what they were and started pulling them, so hopefully these young plants aren't leaving enough root material underground to continue to grow, but there are established "nuts" sending up new shoots as well. Will continue to pull, and hopefully fully eradicate this year.
on: 2019-07-24 22:18:54
I've been getting this in the garden the last several years. Had a neighbor who had bird feeders & she thought it might be coming from that. I pull it but have more & more every year. It's all over the neighborhood. Just identified it. Will be pulling it with even more determination.
on: 2020-07-03 23:47:44
These are growing in our neighbors field road. I picked them last fall for interesting dried arrangement. I did not know they were invasive non natives. I have also noticed it in our ditch as well, but haven't seen it for years there.
on: 2020-08-01 11:38:46
I just pulled up a cluster of this surrounding a sign across the street from my home. Now I worry that just pulling them up didn't kill them -- I saw no tubers.
on: 2020-08-01 16:31:04
Ellen, the tubers are pretty small and easy to miss, plus they often break off and remain in the soil when a plant is uprooted.
on: 2022-08-21 22:28:54
Noticed this disgusting invasive weed about 10 yrs ago after using a bagged compost in veggie garden, ingredients were something like "cow manure and composted reed sedge." After seeing the incredible tenacity -- does not die from smothering with 4 layers cardboard-- I dug out each spike and the tiny nut, putting it all in garbage. Do NOT compost this weed! Have gotten it in control in my veggie garden BUT sadly all my neighbors with commercial lawn service have no idea, and refuse to get on hands & knees to dig this stuff up. It appears on the edges of their lawns, and in low-lying damp areas, as well as disturbed areas (where the snow plow scraped edge of their lawn). Chemicals do not work on this weed. If anyone relied on this for food-- good luck -- the nut is buried 4 inches below surface and is smaller than a green pea.
on: 2023-08-09 16:01:06
This is THE major weed that we are battling in the native plant pollinator garden that we planted last year. Fortunately it is very easy to pull. Unfortunately it seems to grow back pretty quickly. We have a great group of volunteers in the Native Plant Garden Club in Plymouth and everyone understands that battling the yellow nutsedge is our top priority right now. I am hopeful that by pulling it out over and over again, AND by giving it competition in the form of desirable native plants, we are making progress.