Cyperus involucratus Rottb., Cyperaceae

Click on an image for links to BIGGER PICTURES

Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Risk assessment results:  High risk, score: 17 (Go to the risk assessment)

Other Latin names:  Cyperus alternifolius L. subsp. flabelliformis Kük.; Cyperus flabelliformisRottb.

Common name(s): [more details]

Chinese: feng che cao

English: dwarf papyrus grass, flat sedge, umbrella papyrus, umbrella plant, umbrella sedge

French: souchet à feuilles alternes

Hawaiian: ‘ahu‘awa haole, pu‘uka‘a haole

Spanish: juncia de estanque, quitasol chino

Habit:  sedge

Description:  "Robust plants, tufted, with culms up to 12-0 cm tall; involucral bracts large, leaflike, crowded in a close spiraled arrangement at ends of culms, up to 30 cm long and 2 cm wide; umbels to 7 cm broad, on rays up to 10 cm long; spikes about 3 cm long, spikelets pale green, crowded at the tip of the ray; achenes trigonal" (Stone, 1970; pp. 167-168).

"Tall perennial, with short, woody rhizome; culms subdensely tufted, 50-150 cm tall, obtusely trigonous to nearly terete below, scabrous below the corymb, clothed at base with bladeless sheaths only; basal sheaths pale greenish, 10-20 long, ample, subdense, 15-30 cm across, decompound; primary rays numerous, slender, 7-10 cm long, each bearing 4-10 raylets 1-1.5 cm long; leafy bracts many, nearly equal in length, about twice as long as corymb, stiff, flattish, 2-12 mm broad, sub-abruptly acute at apex; spikelets clustered at apices of raylets, lance-oblong to elliptic, flattened, 3-9 mm long, 1.7-3 mm broad, densely 6-30-flowered, light green; rachilla not winged; glumes ovate, acute at apex, about 2 mm long, membranous, pale green and variegated with rusty-brown, 3- or 5-nerved, the keel prominent; achenes ovate-elliptic, 3-sided, 1/3 to 1/4 as long as glume, maturing brown; style nearly as long as achene; stigmas 3, elongated; stamens 3" (Smith, 1979; p. 251).

Habitat/ecology:  Wet places at low elevations. In Hawai‘i, "cultivated and naturalized in marshy areas and along streams, 0-460 m" (Wagner et al., 1999; pp. 1395, 1899). In New Caledonia, "peu cultivé mais occupe parfois des superficies importantes en terrain humide" (MacKee, 1994; p. 47). In New Zealand, "spread by seed from garden centres and domestic gardens and is proving a persistent weed, with Carex comans, in roadside gutter channels" (Healy & Edgar, 1980; p. 187).

Propagation:  Seed, rhizomes.

Native range:  Tropical Africa and the Arabian peninsula; also cultivated and naturalized (GRIN).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
American Samoa Manu‘a Islands	Ta‘u Island	introduced cultivated	Space, James C./Flynn, Tim (2000) (p. Field notes.)
Australia (Pacific offshore islands) Lord Howe Island	Lord Howe Island	introduced	Pickard, J. (1984) (p. 204)
Australia (Pacific offshore islands) Lord Howe Island	Lord Howe Island	introduced invasive cultivated	Orchard, Anthony E., ed. (1994) (p. 22) "In damp soil as an escape from cultivation". Voucher cited: J. Pickard 1207 (NSW)
Australia (Pacific offshore islands) Norfolk Islands	Norfolk Island	introduced invasive cultivated	Orchard, Anthony E., ed. (1994) (p. 11) "In damp soil as an escape from cultivation". Voucher cited: W.R. Sykes NI 661 (CHR)
Chile (offshore islands) Juan Fernández Islands	Isla Más a Tierra (Robinson Crusoe Island)	introduced invasive cultivated	Atkinson, Rachel/Sawyer, John (2011)
Chile (offshore islands) Juan Fernández Islands	Isla Más a Tierra (Robinson Crusoe Island)	introduced cultivated	Danton, Philippe/Perrier, Christophe/Martinez Reyes, Guido (2006) (pp. 481, 527, 553) "Está presente en un único jardin del pueblo de San Juan Bautista".
Cook Islands Southern Cook Islands	Aitutaki Atoll	introduced invasive cultivated	Space, James C./Flynn, Tim (2002) (p. 7)
Cook Islands Southern Cook Islands	Aitutaki Atoll		Bishop Museum (Honolulu) (1969) (voucher ID: BISH 81953) Taxon name on voucher: Cyperus involucratus Roxb.
Cook Islands Southern Cook Islands	Aitutaki Atoll		Bishop Museum (Honolulu) (1969) (voucher ID: BISH 81958) Taxon name on voucher: Cyperus involucratus Roxb.
Cook Islands Southern Cook Islands	Mangaia Island		Bishop Museum (Honolulu) (1928) (voucher ID: BISH 110170) Taxon name on voucher: Cyperus involucratus Roxb.
Cook Islands Southern Cook Islands	Rarotonga Island	introduced invasive cultivated	Space, James C./Flynn, Tim (2002) (p. 7)
Cook Islands Southern Cook Islands	Rarotonga Island		Bishop Museum (Honolulu) (1929) (voucher ID: BISH 110171) Taxon name on voucher: Cyperus flabelliformis Rottb.
Cook Islands Southern Cook Islands	Rarotonga Island		Bishop Museum (Honolulu) (1929) (voucher ID: BISH 110790) Taxon name on voucher: Cyperus flabelliformis Rottb.
Cook Islands Southern Cook Islands	Rarotonga Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (1978) (voucher ID: PTBG 41595) Taxon name on voucher: Cyperus involucratus
Ecuador (Galápagos Islands) Floreana Group	Floreana Island	introduced invasive cultivated	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) Isabela Group	Isabela Island	introduced invasive cultivated	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) Isabela Group	Volcán Sierra Negra, Isabela Island	introduced invasive cultivated	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) San Cristóbal Group	San Cristóbal Island	introduced invasive cultivated	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) Santa Cruz Group	Santa Cruz Island	introduced invasive cultivated	Charles Darwin Foundation (2008)
Federated States of Micronesia Chuuk Islands	Chuuk Islands		Swarbrick, John T. (1997) (p. 90)
Federated States of Micronesia Kosrae Island	Kosrae Island	introduced cultivated	Lorence, David H./Flynn, Timothy (2010) (p. 7) As Cyperus alternifolius L. subsp. flabelliformis (Rottb.) Kük. C.
Federated States of Micronesia Pohnpei Islands	Pohnpei Island	introduced cultivated	Herrera, Katherine/Lorence, David H./Flynn, Timothy/Balick, Michael J. (2010) (p. 41) As Cyperus alternifolius L. subsp. flabelliformis Kük
Fiji Fiji Islands	Viti Levu Island	introduced invasive cultivated	Smith, Albert C. (1979) (p. 251) Vouchers cited: DA 10891, Greenwood 985, DA 1210, DA L.11695, DA 10848
Fiji Fiji Islands	Viti Levu Island		Bishop Museum (Honolulu) (1957) (voucher ID: BISH 34171) Taxon name on voucher: Cyperus involucratus Roxb.
Fiji Fiji Islands	Viti Levu Island		Bishop Museum (Honolulu) (1943) (voucher ID: BISH 110450) Taxon name on voucher: Cyperus involucratus Roxb.
French Polynesia Marquesas Islands	Hiva Oa Island	introduced invasive	Lorence, David H./Wagner, Warren L. (2013)
French Polynesia Marquesas Islands	Nuku Hiva (Nukahiva) Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) Naturalisée
French Polynesia Marquesas Islands	Ua Pou (Huapu, Uapou, Uapu) Island	introduced invasive	Lorence, David H./Wagner, Warren L. (2013)
French Polynesia Society Islands	Raiatea (Havai) Island	introduced invasive cultivated	Welsh, S. L. (1998) (p. 314) Vouchers cited: Moore 154, Florence 3679
French Polynesia Society Islands	Raiatea (Havai) Island		Bishop Museum (Honolulu) (1982) (voucher ID: BISH 492143) Taxon name on voucher: Cyperus involucratus Roxb.
French Polynesia Society Islands	Tahiti Island	introduced invasive cultivated	Welsh, S. L. (1998) (p. 314) Voucher cited: Setchell & Parks 149
French Polynesia Society Islands	Tahiti Island	introduced cultivated	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) Voucher cited: J. Florence 6610 (PAP) Ornementale peu commune.
French Polynesia Tuamotu Archipelago	Moruroa Atoll	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) Naturalisée
French Polynesia Austral (Tubuai) Islands	Rurutu Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) Naturalisée
Guam Guam Island	Guam Island	introduced cultivated	Stone, Benjamin C. (1970) (pp. 167-168) Vouchers cited: Stone 4383 (GUAM), Nelson 550, G.E.S. 210
Guam Guam Island	Guam Island	introduced	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 65)
Guam Guam Island	Guam Island		Bishop Museum (Honolulu) (year unknown) (voucher ID: BISH 110537) Taxon name on voucher: Cyperus flabelliformis Rottb.
Guam Guam Island	Guam Island		Bishop Museum (Honolulu) (year unknown) (voucher ID: BISH 110540) Taxon name on voucher: Cyperus flabelliformis Rottb.
Guam Guam Island	Guam Island		Bishop Museum (Honolulu) (1919) (voucher ID: BISH 110541) Taxon name on voucher: Cyperus flabelliformis Rottb.
State of Hawaii Hawaiian Islands	Hawai‘i (Big) Island	introduced invasive	Imada, Clyde T./Staples, George W./Herbst, Derral R. (2000) (p. 11) Voucher cited: C. Imada 99-26 (BISH)
State of Hawaii Hawaiian Islands	Kaua‘i Island	introduced invasive cultivated	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 1395, 1899)
State of Hawaii Hawaiian Islands	Lāna‘i Island	introduced invasive	Imada, Clyde T./James, Shelly A./Kennedy, Barbara H. (2008) (p. 12) Voucher cited: C. Imada, S. James & P. Imada 2007-18 (BISH)
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive cultivated	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 1395, 1899)
State of Hawaii Hawaiian Islands	Moloka‘i Island	introduced invasive	Oppenheimer, Hank (2007) (p. 23) Voucher cited: Oppenheimer H80506 (BISH, PTBG).
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced invasive cultivated	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 1395, 1899)
Japan (offshore islands) Ogasawara (Bonin) Islands	Bonin (Ogasawara) Islands	introduced invasive	Toyoda, Takeshi (2003) (p. 295) Naturalized
Japan (offshore islands) Ogasawara (Bonin) Islands	Bonin (Ogasawara) Islands	introduced	Kato, Hidetoshi (2007)
Kiribati Tungaru (Gilbert) Islands	Tarawa Atoll		Swarbrick, John T. (1997) (p. 90)
Kiribati Tungaru (Gilbert) Islands	Tarawa Atoll	introduced cultivated	Space, James C./Imada, Clyde T. (2004) (p. 11)
Marshall Islands Ralik Chain	Jaluit (Jãlwõj) Atoll	introduced	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 65)
Marshall Islands Ralik Chain	Kwajalein (Kuwajleen) Atoll	introduced cultivated	Whistler, W. A./Steele, O. (1999) (p. 104)
Marshall Islands Ratak Chain	Majuro (Mãjro) Atoll	introduced cultivated	Vander Velde, Nancy (2003) (p. 37)
Nauru Nauru Island	Nauru Island	introduced cultivated	Thaman, R. R./Fosberg, F. R./Manner, H. I./Hassall, D. C. (1994) (p. 49)
New Caledonia New Caledonia Archipelago	Île Grande Terre	introduced invasive cultivated	MacKee, H. S. (1994) (p. 47) Cyperus alternifolius L.; vouchers cited: Franc 1300, Buchholz 1492, MacKee 2545, MacKee 25699, MacKee 28758. Cyperus flabelliformis Rottb.; voucher cited: MacKee 27697 Spontané
New Caledonia New Caledonia Archipelago	Île Grande Terre		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (1982) (voucher ID: PTBG 22984) Taxon name on voucher: Cyperus alternifolius
Niue Niue	Niue Island	introduced cultivated	Sykes, W. R. (1970) (p. 226) Voucher cited: CHR 150610
Niue Niue	Niue Island	introduced	Whistler, W. A. (1988) (p. 41)
Niue Niue	Niue Island	introduced	Space, James C./Flynn, Tim (2000) (p. 23) Voucher: Flynn 6698 (PTBG, US, NIUE)
Niue Niue	Niue Island	introduced cultivated	Yuncker, T. G. (1943) (p. 25) Voucher cited: Yuncker 9906 (BISH)
Niue Niue	Niue Island	introduced invasive	Space, James C./Waterhouse, Barbara M./Newfield, Melanie/Bull, Cate (2004) (p. 41)
Niue Niue	Niue Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (2000) (voucher ID: PTBG 30170) Taxon name on voucher: Cyperus involucratus Roxb.
Palau Palau (Belau ) (main island group)	Koror (Oreor) Island	introduced	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 65)
Palau Palau (Belau ) (main island group)	Koror (Oreor) Island	introduced cultivated	Space, James C./Waterhouse, Barbara/Miles, Joel E./Tiobech, Joseph/Rengulbai, Kashgar (2003) (pp. 12, 80)
Palau Palau (Belau ) (main island group)	Koror (Oreor) Island		Bishop Museum (Honolulu) (1950) (voucher ID: BISH 110509) Taxon name on voucher: Cyperus involucratus Roxb.
Palau Palau (Belau ) (main island group)	Koror (Oreor) Island		Beleu National Museum (Republic of Palau. Koror.) (1966) (voucher ID: BNM 98) Taxon name on voucher: Cyperus alternifolius L.
Palau Palau (Belau ) (main island group)	Koror (Oreor) Island		Beleu National Museum (Republic of Palau. Koror.) (1968) (voucher ID: BNM 1046) Taxon name on voucher: Cyperus alternifolius L.
Philippines Philippine Islands	Philippine Islands	introduced invasive cultivated	Merrill, Elmer D. (1925) (p. 105) Cultivated for ornamental purposes, occasional in waste places but scarcely established.
Samoa Western Samoa Islands	Savai‘i Island	introduced invasive cultivated	Space, James C./Flynn, Tim (2002) (p. 12)
Samoa Western Samoa Islands	Upolu Island	introduced invasive cultivated	Space, James C./Flynn, Tim (2002) (p. 12)
Tonga Tongatapu Group	Tongatapu Island	introduced invasive	Space, James C./Flynn, Tim (2001) (p. 52)
Tonga Tongatapu Group	Tongatapu Island		Whistler, W. A. (1992) (p. 84) Voucher cited: Ilolahia 127
Tonga Tongatapu Group	Tongatapu Island	introduced invasive	Yuncker, T. G. (1959) (p. 68) Voucher cited: Yuncker 15199
Tonga Vava‘u Group	Vava‘u Island	introduced invasive	Space, James C./Flynn, Tim (2001) (p. 65)
Tuvalu Tuvalu (Ellis) Islands	Nui Atoll		Woodroffe, C. D. (1985) (p. 10)
Tuvalu Tuvalu (Ellis) Islands	Tuvalu Islands		Swarbrick, John T. (1997) (p. 90)
United States (other Pacific offshore islands) Midway Atoll	Midway Atoll	introduced invasive cultivated	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 1395, 1899)
United States (other Pacific offshore islands) Midway Atoll	Sand Island	introduced invasive	Starr, Forest/Starr, Kim/Loope, Lloyd (2008) (pp. B-7)
Wallis and Futuna Wallis and Futuna (Horne) Islands	Wallis (‘Uvea) Island	introduced cultivated	Meyer, Jean-Yves (2007) (p. 25)

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)	Queensland	introduced invasive	Queensland Herbarium (2002) (p. 3)
Central America Central America (Pacific rim)	Costa Rica (Republic of)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Naturalized
China China	China (People's Republic of)	introduced invasive cultivated	Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2013) Cultivated as an ornamental in China, sometimes escaped and naturalized along streams and in wet thickets and disturbed areas; below 400 m. Guangdong, Hunan
China China	Hong Kong	introduced invasive cultivated	Wu, Te-lin (2001) (p. 309) As Cyperus flabelliformis Rottb.
Indonesia Indonesia	Indonesia (Republic of)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Naturalized
Mexico Mexico	Mexico (United Mexican States)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Naturalized
New Zealand New Zealand	New Zealand (country)	introduced invasive	Healy, A. J./Edgar, E. (1980) (p. 187) Voucher cited: H. B. Matthews (CHR 5173)
Singapore Singapore	Singapore (Republic of)	introduced cultivated	Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. (2009) (p. 31) Cyperus alternifolius L. Cultivated only.
South America (Pacific rim) South America (Pacific rim)	Chile (Republic of)		Hafliger, E. (1092) (p. 10)
Taiwan Taiwan Island	Taiwan Island	introduced invasive cultivated	Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2013) Cultivated as an ornamental, sometimes escaped and naturalized along streams and in wet thickets and disturbed areas; below 400 m.
Thailand Thailand	Thailand (Kingdom of)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Naturalized
United States (west coast) United States (west coast states)	USA (California)	introduced	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)

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	introduced cultivated	Swarbrick, J. T. (1997) (p. 111)
La Réunion (France) La Réunion Island	La Réunion Island	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Mauritius Mautitius Islands (Mauritius and Rodrigues)	Mauritius Island	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
French Territory of Mayotte Mayotte Islands	Mayotte Island	introduced cultivated	Comité français de l'Union Internationale pour la Conservation de la Nature en France (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	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)
United States (continental except west coast) United States (other states)	USA (Florida)	introduced	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)

Comments:  Common along streamsides on Rarotonga and invading wet areas on Aitutaki, Cook Islands (Space & Flynn, 2002).

Very prevalent in wet areas, Tongatapu, Tonga (Space & Flynn, 2001).

Control:  If you know of control methods for Cyperus involucratus, please let us know.