Pacific Island Ecosystems at Risk (PIER)

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Cyperus esculentus
L., Cyperaceae
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Present on Pacific Islands?  no

Primarily a threat at high elevations?  no

Risk assessment results:  Reject, score: 19 (Go to the risk assessment).

Common name(s): [more details]

Chinese: you suo cao

English: chufa, earth almond, nutgrass, tigernut, watergrass, yellow nut grass, yellow nut grass, yellow nutsedge

French: amande de terre, choufa, souchet comestible

Korean: gireumgol

Spanish: cebollín, chufa, chufa commún, coco, coquillo, coquillo amarillo, coquito, coyolillo, juncia, juncia avellanada

Habit:  sedge

Description:  "Perennials with fibrous roots, stolons filiform, elongate, covered with pale brown scales, terminated by a small tuber; culms solitary, slender, trigonous, smooth, (10-) 25-50 cm tall, thickened at base with a small corm-like enlargement clothed with brown fibers.  Leaves basal, several per culm, blades linear, 3-6 mm wide, shorter than to longer than the culm; sheaths reddish brown; ligule absent.  Inflorescence an open umbelliform corymb, simple or partially compound, 4-7 cm long and as wide, primary rays slender, 5-8, spreading, 1-4 cm long, spikes ovoid, loosely bearing 5-14 spikelets; involucral bracts 3-6, leaf-like, spreading, the lower 1-2 surpassing the inflorescence; spikelets 8-16-flowered, yellowish brown or pale brown, linear-oblong to oblong, slightly compressed, 5-12 mm long, ca. 2 mm wide, rachilla winged; glumes yellowish brown or reddish brown, upper margins membranous, hyaline, ovate or ovate-elliptic, 1.6-2.2 mm long, 7-nerved, apex and keel obtuse; stigmas 3.  Achenes grayish brown, glossy, obovate or oblong-obovate, obtusely trigonous, 1.5-1.8 mm long, minutely puncticulate.  Separation of this species from the very similar Cyperus rotundus is often difficult.  Cyperus eesculentus is generally larger than C. rotundus, and the glumes of the former are yellow rather than reddish brown in the latter.  The most reliable character, however, is the presence of a short ligule on the leaves of C. rotundus; this is absent on the leaves of C. esculentus"  (Wagner et al., 1999; p. 1396).

Habitat/ecology:  "The weed is found on low ground, moist fields, in heavily irrigated crops, along river banks and roadsides, and in ditches.  It tolerates high soil moisture much better than does C. rotundus.  The species grows very well on all soil types, including black peat soils, and performs equally well at pH ranges from 5 to 7.  It is quite intolerant of shade"  (Holm et al., 1977; pp. 125-133).

In New Zealand, "a weedy plant, troublesome overseas in gardens and cultivated land" (Healy & Edgar, 1980; p. 186).

Propagation:  Seed

Native range:  "Southern Europe, Mediterranean region, South Africa, North America, and the Andean region of South America" (Wagner et al., 1999; p. 1396).

Presence:

Pacific
Country/Terr./St. &
Island group
Location Cited status &
Cited as invasive &
Cited as cultivated &
Cited as aboriginal introduction?
Reference &
Comments
State of Hawaii
Hawaiian Islands
Hawai‘i (Big) Island introduced
invasive
Strong, Mark T./Wagner, Warren L. (1997) (p. 41)
Voucher cited: Stemmermann 6889 (BISH)
State of Hawaii
Hawaiian Islands
Kaua‘i Island introduced
invasive
Wood, K. R. (2006) (p. 17)
Voucher cited: K.R. Wood & S. Perlman 5103 (AD, BISH, F, K, MO, NY, PTBG, US)
Pacific Rim
Country/Terr./St. &
Island group
Location Cited status &
Cited as invasive &
Cited as cultivated &
Cited as aboriginal introduction?
Reference &
Comments
Australia
Australia (continental)
New South Wales introduced
invasive
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Naturalized
Australia
Australia (continental)
Queensland introduced
invasive
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Naturalized
Cambodia
Cambodia
Cambodia (Kingdom of)   Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 127)
Canada (British Colombia)
Province of British Columbia
Canada (British Columbia) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Chile (continental)
Chile
Chile (Republic of)   Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 127)
China
China
China (People's Republic of) introduced
invasive
cultivated
Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2013)
var. sativus Boeckeler. Cultivated in Guangxi, Heilongjiang, Liaoning, Xinjiang, and Yunnan; collected as a naturalized plant in Shandong and perhaps elsewhere.
Colombia
Colombia
Colombia (Republic of) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Costa Rica
Costa Rica
Costa Rica (Republic of) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Ecuador (Mainland)
Ecuador
Ecuador (Republic of) (continental) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Indonesia
Indonesia
Indonesia (Republic of) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Java
Japan
Japan
Japan (country) introduced
Mito, Toshikazu/Uesugi, Tetsuro (2004) (p. 193)
Mexico
Mexico
Mexico (United Mexican States) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
New Zealand
New Zealand
New Zealand (country) introduced
invasive
Healy, A. J./Edgar, E. (1980) (p. 186)
Voucher cited: G. S. Harris (CHR 83385)
Nicaragua
Nicaragua
Nicaragua (Republic of)   Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (pp. 127, 133)
Panama
Panama
Panama (Republic of) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Perú
Perú
Perú (Republic of) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Taiwan
Taiwan Island
Taiwan Island introduced
invasive
cultivated
Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2013)
var. sativus Boeckeler. Cultivated and naturalized.
Thailand
Thailand
Thailand (Kingdom of)   Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 133)
United States (west coast)
United States (west coast states)
USA (Oregon) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
United States (west coast)
United States (west coast states)
USA (California) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
United States (west coast)
United States (west coast states)
USA (Washington) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Vietnam
Vietnam
Vietnam (Socialist Republic of) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Indian Ocean
Country/Terr./St. &
Island group
Location Cited status &
Cited as invasive &
Cited as cultivated &
Cited as aboriginal introduction?
Reference &
Comments
Comoros
Comoro Islands
Comoro Islands native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Mauritius
Mautitius Islands (Mauritius and Rodrigues)
Mauritius Island   McIntyre, Guy (1991) (p. 47)
Also reported from
Country/Terr./St. &
Island group
Location Cited status &
Cited as invasive &
Cited as cultivated &
Cited as aboriginal introduction?
Reference &
Comments
Canada (except British Colombia)
Canada
Canada (country) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
New Brunswick, Ontario, Quebec
United States (continental except west coast)
United States (other states)
United States (other states) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
United States (continental except west coast)
United States (other states)
USA (Florida) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)


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This page was created on 21 NOV 2005 and was last updated on 5 MAR 2010.