Pacific Island Ecosystems at Risk (PIER)

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Cyperus iria
L., Cyperaceae
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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Common name(s): [more details]

Bikol: taga-taga

Bontoc: okoiang

Chinese: sui mi suo cao

English: grasshopper's cyperus, rice flat sedge, ricefield flatsedge, umbrella sedge

Filipino: alinang, paiung-paiung

Japanese: kogomegawatsuri

Palauan: badel aus

Tahitian: mou, mou hairi

Habit:  sedge

Description:  "Cespitose herb, culms to 50 cm tall, few leaves; leaves shorter than culm; bracts longer than inflorescence; inflorescence branched, spikes about 2.5 cm long, about 10-12-flowered; spikelets 6 mm long, glumes spreading, scarcely imbricate, apex rounded with a tiny mucro, pale straw-colored, but green-carinate; achene narrowly obovoid, yellow-brown, trigonal, minutely apiculate"  (Stone, 1970; P. 167).

"Annual, with fibrous roots only; culms solitary or a few together, erect, 8-60 cm tall, slender or slightly thick, trigonous, smooth; leaves 2 or 3 to a culm, much shorter than culm; blades linear, 2-5 mm broad, weakly folded; sheaths reddish or somewhat purplish brown; corymbs as a rule compound, 5-15 cm long, 3-10 cm broad, with 3-7 unequal rays 2-12 cm long, each bearing 5-10 spikes; spikes often more or less inclined, elliptic-ovate, 1-4 cm long, bearing 4-20 spikelets; leafy bracts 4 or 5, the lowest 2 or 3 surpassing the corymb; spikelets rather loosely disposed, erect-patent, oblong-elliptic or lanceolate, 4-9 mm long, 1.7-2 mm broad, flattened, 6-22-flowered; rhachilla hardly winged; glumes subloosely disposed, obovate-orbicular, 1-1.5 mm long, truncate to shallowly retuse at the usually nucronulate apex, thinly herbaceous, yellow or slightly straw-colored, pale on hyaline upper margin, 3- or 5-nerved, convex on the green keel; achenes obovate, 3-sided, nearly equalling the glume, maturing dark brown; style short, about 1/3 as long as achene; stigmas 3, stamens 3" (Smith, 1979; pp. 250-251).

Illustration by International Rice Research Institute (IRRI) courtesy Ecoport.

Habitat/ecology:  "It is mainly a weed of open, wet places"  (Holm et al., 1977; p. 240).  In Fiji, "a naturalized adventive, often locally abundant on Viti Levu from sea level to 300 m, along roadsides and in swamps, cultivated areas, and especially in rice fields" (Smith, 1979; pp. 250-251).

Propagation:  Seed

Native range:  "East Africa and central Asia through India to China and Japan, eastward to Malesia and Australia" (Smith, 1979; pp. 250-251).

Presence:

Pacific
Country/Terr./St. &
Island group
Location Cited status &
Cited as invasive &
Cited as cultivated &
Cited as aboriginal introduction?
Reference &
Comments
Commonwealth of the Northern Mariana Islands (US)
Northern Mariana Islands
Saipan Island native
Raulerson, L. (2006) (p. 13)
Federated States of Micronesia
Chuuk Islands
Weno (Moen) Island native
Space, James C./Waterhouse, Barbara/Denslow, Julie S./Nelson, Duane/Mazawa, Thomas R. (2000) (p. Voucher specimen)
Voucher: BMW 5788 (BISH, BRI)
Federated States of Micronesia
Chuuk Islands
Weno (Moen) Island   Wagner, W. L./ Herbst, D. R./Weitzman, A./Lorence, D.H. (2013)
Fiji
Fiji Islands
Viti Levu Island introduced
invasive
Smith, Albert C. (1979) (pp. 250-251)
Vouchers cited: Greenwood 806B, DA 10556, DA 2845, DA 7818, DA 7987, DA 8685, DA 6093, DA 8617
Guam
Guam Island
Guam Island native
invasive
Stone, Benjamin C. (1970) (p. 167)
Voucher cited: Necker 68
Guam
Guam Island
Guam Island native
Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 66)
Japan (offshore islands)
Ogasawara (Bonin) Islands
Bonin (Ogasawara) Islands introduced
Kato, Hidetoshi (2007)
Nauru
Nauru Island
Nauru Island introduced
invasive
Thaman, R. R./Fosberg, F. R./Manner, H. I./Hassall, D. C. (1994) (p. 50)
Voucher cited: Thaman & Manner 90a (SUVA)
Rare
New Caledonia
New Caledonia
New Caledonia Islands   Swarbrick, John T. (1997) (p. 90)
New Caledonia
New Caledonia Archipelago
Île Grande Terre introduced
invasive
Tassin, Jacques (2005)
New Caledonia
New Caledonia Archipelago
Île Grande Terre introduced
MacKee, H. S. (1994) (p. 48)
Vouchers cited: MacKee 28356, MacKee 29833, MacKee 36714
Palau
Palau (Belau ) (main island group)
Babeldaob Island native
Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 66)
Palau
Palau (Belau ) (main island group)
Koror (Oreor) Island native
Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 66)
Palau
Palau (Belau ) (main island group)
Malakal (Ngemelachel) Island native
Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 66)
Papua New Guinea
Papua New Guinea (eastern New Guinea Island)
Papua New Guinea (eastern New Guinea Island) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Philippines
Philippine Islands
Philippine Islands native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Philippines
Philippine Islands
Philippine Islands   Merrill, Elmer D. (1925) (p. 106)
In open wet places; a common and characteristic rice paddy weed.
Solomon Islands
Solomon Islands
Solomon Islands   Swarbrick, John T. (1997) (p. 90)
Solomon Islands
Solomon Islands
Solomon Islands native
Hancock, I. R./Henderson, C. P. (1988) (p. 62)
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)
Australia (continental) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
South Australia, Western Australia
Australia
Australia (continental)
New South Wales native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Australia
Australia (continental)
Northern Territory native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Australia
Australia (continental)
Queensland native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Cambodia
Cambodia
Cambodia (Kingdom of) native
Waterhouse, D. F. (1993) (pp. 64, 77)
China
China
China (People's Republic of) native
Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2013)
Forest margins, under shrubs or forests, grasslands by water, mountain slopes, along trails in valleys, river margins, wet places, paddy fields; below 100-2000 m. Anhui, Chongqing, Fujian, S Gansu, Guangdong, Guangxi, Guizhou, Hainan, Hebei, Heilongjiang, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Jilin, Liaoning, S Shaanxi, Shandong, Shanxi, Sichuan, Xinjiang, SE Xizang, Yunnan, Zhejiang.
China
China
Hong Kong native
Wu, Te-lin (2001) (p. 310)
In wet places and paddy fields.
Costa Rica
Costa Rica
Costa Rica (Republic of) introduced
invasive
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Naturalized
Ecuador (Mainland)
Ecuador
Ecuador (Republic of) (continental) introduced
invasive
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Naturalized
Indonesia
Indonesia
Indonesia (Republic of) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Japan
Japan
Japan (country) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Honshu, Kyushu, Shikoku
Japan
Ryukyu Islands
Ryukyu Islands native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
North Korea
North Korea
North Korea (Democratic People's Republic of) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
South Korea
South Korea
South Korea (Republic of) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Malaysia
Malaysia
Malaysia (country of) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Mexico
Mexico
Mexico (United Mexican States) introduced
invasive
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Naturalized
Negara Brunei Darussalam
Brunei
Brunei (Negara Brunei Darussalam) native
Waterhouse, D. F. (1993) (pp. 64, 77)
Panama
Panama
Panama (Republic of) introduced
invasive
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Naturalized
Perú
Perú
Perú (Republic of) introduced
invasive
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Naturalized
Singapore
Singapore
Singapore (Republic of) native
Waterhouse, D. F. (1993) (pp. 64, 77)
Singapore
Singapore
Singapore (Republic of) uncertain if introduced
invasive
Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. (2009) (p. 31)
Weed of uncertain origin
Taiwan
Taiwan Island
Taiwan Island native
Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2013)
Forest margins, under shrubs or forests, grasslands by water, mountain slopes, along trails in valleys, river margins, wet places, paddy fields; below 100-2000 m.
Thailand
Thailand
Thailand (Kingdom of) native
Waterhouse, D. F. (1993) (pp. 64, 77)
United States (west coast)
United States (west coast states)
USA (California) introduced
invasive
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Naturalized
Vietnam
Vietnam
Vietnam (Socialist Republic of) native
Waterhouse, D. F. (1993) (pp. 64, 77)
Indian Ocean
Country/Terr./St. &
Island group
Location Cited status &
Cited as invasive &
Cited as cultivated &
Cited as aboriginal introduction?
Reference &
Comments
Australia (Indian Ocean offshore islands)
Christmas Island Group
Christmas Island extirpated
Swarbrick, J. T. (1997) (p. 111)
British Indian Ocean Territory
Chagos Archipelago
Diego Garcia Island   Topp, J. M. W. (1988) (p. 18)
British Indian Ocean Territory
Chagos Archipelago
Diego Garcia Island introduced
invasive
Whistler, W. Arthur (1996) (p. 23)
Mauritius
Mautitius Islands (Mauritius and Rodrigues)
Mauritius Island native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Also reported from
Country/Terr./St. &
Island group
Location Cited status &
Cited as invasive &
Cited as cultivated &
Cited as aboriginal introduction?
Reference &
Comments
United States (continental except west coast)
United States (other states)
United States (other states) introduced
invasive
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Naturalized
United States (continental except west coast)
United States (other states)
USA (Florida) introduced
invasive
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Naturalized


Need more info? Have questions? Comments? Information to contribute? Contact PIER! (pier@hear.org)

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This page was created on 1 JAN 1999 and was last updated on 11 JAN 2007.