Eleocharis geniculata (L.) Roem. & Schult., Cyperaceae

Click on an image for links to BIGGER PICTURES

Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Common name(s): [more details]

English: spike rush, spikerush

French: scirpe genouillé

I-Kiribati: te maunei

Kwara‘ae: ngwano

Maori (Cook Islands): remu, rimu

Marshallese: kube in jemin, kubwe in jenen Iniriñ, pãdãdijmaan, pãdãlimaan

Palauan: kerdikes

Spanish: cebolleta de pantano, junco de espiga elegante, mara, piso

Habit:  sedge

Description:  "Annuals, culms densely tufted, pale or green and slightly glaucous, filiform, 7-30 cm tall, 0.2-0.5 mm in diameter.  Sheaths pale green, often tinged reddish brown in lower part, o.5-3 cm long, orifice truncate.  Spikelets many-flowered, rusty or pale brown, broadly ovoid to ovoid-ellipsoid, 3-7 mm long, 3-4 mm wide, obtuse; glumes pale brown, membranous, broadly elliptic to ovate, ca. 2 mm long, obtuse, the mid-nerve green, ending below the glume apex; bristles 6-7, rusty brown, retrorsely spinulose, slightly longer than the achene; style base depressed-conical, nearly 1/3 as wide as achene; stigmas 2.  Achenes black, glossy, smooth, broadly obovoid, thickly biconvex, ca. 1 mm long"  (Wagner et al., 1999; pp. 1402-1403).

Habitat/ecology:  In Hawai‘i, "naturalized in moist ground, marshy places, salt marshes, taro paddies and seeps, 0-760 m"  (Wagner et al., 1999; pp. 1402-1403).  In Fiji, "a naturalized adventive but apparently not common, occurring between sea level and 200 m in low-lying wet areas near coasts, often in coral sand, or in forest in rocky places"  (Smith, 1979; p. 240).  In Guam, "in marshes, swamps, and at the edges of mangrove swamps. (Stone, 1970; p. 171).

Propagation:  Seed

Native range:  "Widespread in tropical and subtropical regions of both hemispheres"  (Smith, 1979. p. 240).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
American Samoa American Samoa Islands	American Samoa Islands		Waterhouse, D. F. (1997) (p. 61)
American Samoa Swain's Island	Swain's Island	native	Whistler, W. A. (1983) (p. 17) Voucher cited: Whistler 3352A
Commonwealth of the Northern Mariana Islands (US) Northern Mariana Islands	Rota Island	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 69)
Commonwealth of the Northern Mariana Islands (US) Northern Mariana Islands	Saipan Island	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 69)
Cook Islands Northern Cook Islands	Manihiki Atoll		McCormack, Gerald (2008)
Cook Islands Northern Cook Islands	Nassau Island		McCormack, Gerald (2008)
Cook Islands Northern Cook Islands	Rakahanga Atoll		McCormack, Gerald (2008)
Cook Islands Southern Cook Islands	‘Atiu Island		McCormack, Gerald (2008)
Cook Islands Southern Cook Islands	Ma‘uke Island		McCormack, Gerald (2008)
Cook Islands Southern Cook Islands	Miti‘aro Island		McCormack, Gerald (2008)
Cook Islands Southern Cook Islands	Palmerston (Avarau) Island		McCormack, Gerald (2008)
Cook Islands Southern Cook Islands	Rarotonga Island		McCormack, Gerald (2008)
Ecuador (Galápagos Islands) Isabela Group	Isabela Island	possibly introduced invasive	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) Isabela Group	Volcán Sierra Negra, Isabela Island	possibly introduced invasive	Charles Darwin Foundation (2008)
Federated States of Micronesia Chuuk Islands	Losap Atoll	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 69)
Federated States of Micronesia Chuuk Islands	Namonuito (Namonweito, Nómwun Wiité) Atoll	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 69)
Federated States of Micronesia Chuuk Islands	Puluwat (Pwonowót) Atoll	native	Manner, H. I./Mallon, E. (1989) (p. 37) Vouchers cited: Manner & Mallon 139 (GUAM), Manner & Mallon 141 (GUAM)
Federated States of Micronesia Chuuk Islands	Satawan Atoll	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 69)
Federated States of Micronesia Yap Islands	Faraulep (Faraulap) Atoll	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 69)
Federated States of Micronesia Yap Islands	Ulithi Atoll	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 69)
Federated States of Micronesia Yap Islands	Woleai Atoll	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 69)
Federated States of Micronesia Yap Islands	Yap (Waqab) Island	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 69)
Fiji Fiji Islands	Kanathea Island	introduced invasive	Smith, Albert C. (1979) (p. 240) Voucher cited: DA L.14761 Not common.
Fiji Fiji Islands	Kandavu Island	introduced invasive	Smith, Albert C. (1979) (p. 240) Voucher cited: DA 2996 Not common.
Fiji Fiji Islands	Ngau Island	introduced invasive	Smith, Albert C. (1979) (p. 240) Voucher cited: Milne 178 Not common.
Fiji Fiji Islands	Ovalau Island	introduced invasive	Smith, Albert C. (1979) (p. 240) Vouchers cited: DA 14512, Milne 223 Not common.
Fiji Fiji Islands	Viti Levu Island	introduced invasive	Smith, Albert C. (1979) (p. 240) Vouchers cited: Greenwood 925, DA 11863, MacGillivray 22 Not common.
French Polynesia Clipperton Island	Clipperton (Arue, Avera) Island		Sachet, M.-H. (1962) (p. 92)
French Polynesia Society Islands	Huahine Island	introduced invasive	Welsh, S. L. (1998) (pp. 315-316) Voucher cited: McKee 3111
French Polynesia Society Islands	Maupiti (Maurua) Island		Fosberg, F. R. (1997) (p. 38)
French Polynesia Society Islands	Moorea Island	introduced invasive	Welsh, S. L. (1998) (pp. 315-316) Voucher cited: Florence 2148
French Polynesia Society Islands	Raiatea (Havai) Island	introduced invasive	Welsh, S. L. (1998) (pp. 315-316) Vouchers cited: Moore 44, BRY 26481
French Polynesia Society Islands	Taha‘a Island	introduced invasive	Welsh, S. L. (1998) (pp. 315-316) Voucher cited: Fosberg 63495
French Polynesia Society Islands	Tahiti Island	introduced invasive	Welsh, S. L. (1998) (pp. 315-316) Voucher cited: Leland et al. 5
French Polynesia Society Islands	Tetiaroa Atoll	introduced invasive	Sachet, M.-H./Fosberg, F. R. (1983) (p. 38) Vouchers cited: Fosberg & Sachet 54645 (US), Raynal 18016 (P), Fosberg 63772 (US)
French Polynesia Society Islands	Tupai (Tubai) Island	introduced invasive	Welsh, S. L. (1998) (pp. 315-316) Voucher cited: Grant 4834
French Polynesia Society Islands	Tupai (Tubai) Island		Sachet, M.-H. (1983) (p. 14) Voucher cited: Grant 4834 (BISH), Sachet 1985 (US)
Guam Guam Island	Guam Island	native	Stone, Benjamin C. (1970) (p. 171) Vouchers cited: Stone 3868 (GUAM), Stone 4888 (GUAM)
Guam Guam Island	Guam Island	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 69)
State of Hawaii Hawaiian Islands	Kaua‘i Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 1402-1403)
State of Hawaii Hawaiian Islands	Lāna‘i Island	introduced invasive	Imada, Clyde T./James, Shelly A./Kennedy, Barbara H. (2008) (pp. 12-13) Voucher cited: C. Imada, S. James & P. Imada 2007-16 (BISH)
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive	Oppenheimer, Hank L. (2003) (p. 10) West Maui. Vouchers cited: Oppenheimer H40105 (BISH, PTBG), Oppenheimer H110152 (BISH, PTBG)
State of Hawaii Hawaiian Islands	Moloka‘i Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 1402-1403)
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 1402-1403) Voucher cited: Forbes s.n. (BISH)
Kiribati Tungaru (Gilbert) Islands	Butaritari Atoll	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 69)
Kiribati Tungaru (Gilbert) Islands	Butaritari Atoll	introduced invasive	Space, James C./Imada, Clyde T. (2004) (p. 10) Voucher specimens collected: Imada 2003-57 (BISH 697672), Imada 2003-58 (BISH 697673)
Kiribati Tungaru (Gilbert) Islands	Maiana Atoll	introduced invasive	Space, James C./Imada, Clyde T. (2004) (p. 10) Voucher: Imada 2003-107 (BISH 697718)
Kiribati Tungaru (Gilbert) Islands	Marakei Atoll	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 69)
Kiribati Tungaru (Gilbert) Islands	Onotoa Atoll	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 69)
Kiribati Tungaru (Gilbert) Islands	Onotoa Atoll	cultivated	Moul, Edwin T. (1957) (p. 9) Vouchers cited: Moul 8159 (US), Moul 8337 (US), Moul 8210 (US)
Kiribati Tungaru (Gilbert) Islands	Tarawa Atoll	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 69)
Kiribati Tungaru (Gilbert) Islands	Tarawa Atoll	introduced invasive	Space, James C./Imada, Clyde T. (2004) (p. 10) Voucher: Imada 2003-38 (BISH 697653)
Marshall Islands Ralik Chain	Ebon (Epoon) Atoll	native	Fosberg, F. Raymond (1990) (p. 23)
Marshall Islands Ralik Chain	Jaluit (Jãlwõj) Atoll	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 69)
Marshall Islands Ralik Chain	Jaluit (Jãlwõj) Atoll	native	Fosberg, F. R./Sachet, M.-H. (1962) (p. 8) Voucher cited: Fosberg 39466 (US)
Marshall Islands Ralik Chain	Kili (Kõle) Atoll	native	Vander Velde, Nancy/Vander Velde, Brian (2006) (p. 3) "Rare; small patch near grassy area of wetland to the north, not too far from ocean road".
Marshall Islands Ralik Chain	Kwajalein (Kuwajleen) Atoll	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 69)
Marshall Islands Ralik Chain	Kwajalein (Kuwajleen) Atoll	possibly native	Whistler, W. A./Steele, O. (1999) (p. 75) Vouchers cited: Fosberg 41377, Whistler 11237
Marshall Islands Ratak Chain	Ailuk (Aelok) Atoll	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 69)
Marshall Islands Ratak Chain	Ailuk (Aelok) Atoll	introduced invasive	Fosberg, F. R. (1955) (p. 5) Voucher cited: Fosberg 33969 (US)
Marshall Islands Ratak Chain	Arno Atoll	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 69)
Marshall Islands Ratak Chain	Likiep Atoll	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 69)
Marshall Islands Ratak Chain	Likiep Atoll	introduced invasive	Fosberg, F. R. (1955) (p. 5) Voucher cited: Fosberg 33825 (US)
Marshall Islands Ratak Chain	Majuro (Mãjro) Atoll	native	Vander Velde, Nancy (2003) (p. 38) Rare
Marshall Islands Ratak Chain	Maloelap Atoll		Vander Velde, Nancy (year unknown)
Marshall Islands Ratak Chain	Mejit (Mãjej) Island	native	Fosberg, F. Raymond (1990) (p. 23)
Palau Palau (main island group)	Angaur Island	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 69)
Palau Palau (main island group)	Angaur Island		Beleu National Museum (Republic of Palau. Koror.) (1977) (voucher ID: BNM 914) Taxon name on voucher: Eleocharis geniculata (L.) R. & S.
Palau Palau (main island group)	Babeldaob Island	native	Space, James C./Lorence, David H./LaRosa, Anne Marie (2009) (p. Field notes and voucher.) Voucher: Lorence 9815 (BNM, PTBG)
Palau Palau (main island group)	Koror Island	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 69)
Palau Palau (main island group)	Koror Island		Beleu National Museum (Republic of Palau. Koror.) (1977) (voucher ID: BNM 10019) Taxon name on voucher: Eleocharis geniculata (L.) DC.
Philippines Philippine Islands	Philippine Islands		Hafliger, E. (1092) (p. 33)
Solomon Islands Solomon Islands	Solomon Islands		Waterhouse, D. F. (1997) (p. 61)
Solomon Islands Solomon Islands	Solomon Islands	native	Hancock, I. R./Henderson, C. P. (1988) (p. 71)
Tonga Ha‘apai Group	Kao Island	native	Whistler, W. A. (1992) (p. 85) Voucher cited: Yuncker 15974
Tonga Ha‘apai Group	Kao Island		Yuncker, T. G. (1959) (p. 71) Voucher cited: Yuncker 15974

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)		Hafliger, E. (1092) (p. 33)
China China	China (People's Republic of)		Hafliger, E. (1092) (p. 33)
Colombia Colombia	Colombia (Republic of)		Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 138)
Costa Rica Costa Rica	Costa Rica (Republic of)		Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 138)
Indonesia Indonesia	Indonesia (Republic of)		Hafliger, E. (1092) (p. 33)
Mexico Mexico	Mexico (United Mexican States)		Hafliger, E. (1092) (p. 33)

Indian Ocean
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
British Indian Ocean Territory Chagos Archipelago	Diego Garcia Island		Stoddart, D. R./Taylor, J. D., eds. (1971) (p. 147) Voucher cited: Stoddart 800 (K, US)

Additional information:
Additional online information about Eleocharis geniculata is available from the Hawaiian Ecosystems at Risk project (HEAR).

Information about Eleocharis geniculata as a weed (worldwide references) may be available from the Global Compendium of Weeds (GCW).

Taxonomic information about Eleocharis geniculata may be available from the Germplasm Resources Information Network (GRIN).

References:

Beleu National Museum (Republic of Palau. Koror.). 1977. Voucher specimen #BNM10019(Otobed, D.O. PW-10019).

Beleu National Museum (Republic of Palau. Koror.). 1977. Voucher specimen #BNM914(Canfield, J.E. 218).

Charles Darwin Foundation. 2008. Database inventory of introduced plant species in the rural and urban zones of Galapagos. Charles Darwin Foundation, Galapagos, Ecuador.

Charles Darwin Research Station. 2005. CDRS Herbarium records.

Fosberg, F. R. 1955. Northern Marshall Islands Expedition, 1951-1952. Land biota: vascular plants. Atoll Research Bulletin No. 39. Pacific Science Board, National Academy of Sciences, Washington. 22 pp.

Fosberg, F. R. 1997. Preliminary checklist of the flowering plants and ferns of the Society Islands. Ed. by David R. Stoddart. U. Cal. Berkeley.

Fosberg, F. R./Otobed, D./Sachet, M.-H./Oliver, R. L./Powell, D. A./Canfield, J. E. 1980. Vascular plants of Palau with vernacular names. Department of Botany, The Smithsonian Institution, Washington, D.C. 43 pp.

Fosberg, F. R./Sachet, M.-H. 1962. Vascular plants recorded from Jaluit Atoll. Atoll Research Bulletin No. 92. Pacific Science Board, National Academy of Sciences, Washington. 39 pp.

Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce. 1987. A geographical checklist of the Micronesian monocotyledonae. Micronesica 20:1-126.

Fosberg, F. Raymond. 1990. A review of the natural history of the Marshall Islands. Atoll Research Bulletin No. 330. Smithsonian Institution, Washington. 100 pp.

Hafliger, E. 1092. Monocot Weeds 3. CIBA-GEIGY Ltd., Basle, Switzerland. 132 pp. plus plates.

Hancock, I. R./Henderson, C. P. 1988. Flora of the Solomon Islands. Research Bulletin No. 7. Ministry of Agriculture and Lands, Honiara. 203 pp.

Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. 1979. A geographical atlas of world weeds. John Wiley & Sons, New York. 391 pp.

Imada, Clyde T./James, Shelly A./Kennedy, Barbara H. 2008. New plant records from O‘ahu for 2007. In: Evenhuis, Neal L. and Eldredge, Lucias G., eds. Records of the Hawaii Biological Survey for 2007. Bishop Museum Occasional Papers 100:12-16.

Manner, H. I./Mallon, E. 1989. An Annotated list of the vascular plants of Pulawat Atoll. Micronesica 22:23-63.

McCormack, Gerald. 2008. Cook Islands Biodiversity Database, Version 2007.2. Cook Islands Natural Heritage Trust, Rarotonga.

Moul, Edwin T. 1957. Preliminary report on the flora of Onotoa Atoll, Gilbert Islands. Atoll Research Bulletin No. 57. Pacific Science Board, National Academy of Sciences, Washington. 48 pp.

Oppenheimer, Hank L. 2003. New plant records from Maui and Hawai‘i Counties. In: Evenhuis, Neal L. and Eldredge, Lucius G., eds. Records of the Hawaii Biological Survey for 2001-2002. Part 1: Articles. Bishop Museum Occasional Papers. 73:3-30.

Sachet, M.-H. 1962. Geography and land ecology of Clipperton Island. Atoll Research Bulletin No. 86. Pacific Science Board, National Academy of Sciences, Washington. 115 pp.

Sachet, M.-H. 1983. Botanique de l'ile de Tupai, Iles de la Societe. Atoll Research Bulletin No. 276. Smithsonian Institution, Washington. 26 pp. + photos.

Sachet, M.-H./Fosberg, F. R. 1983. An ecological reconnaissance of Tetiaroa Atoll, Society Islands. Atoll Research Bulletin No. 275. Smithsonian Institution, Washington. 67 pp. + photos.

Smith, Albert C. 1979. Flora Vitiensis nova: a new flora of Fiji. National Tropical Botanical Garden, Lawai, Kauai, Hawaii. Volume 1. 494 pp.

Space, James C./Imada, Clyde T. 2004. Report to the Republic of Kiribati on invasive plant species on the islands of Tarawa, Abemama, Butaritari and Maiana. Cont. no. 2003-006 to the Pac. Biol. Surv. USDA Forest Service and Bishop Museum, Honolulu. 103 pp.

Space, James C./Lorence, David H./LaRosa, Anne Marie. 2009. Report to the Republic of Palau: 2008 update on Invasive Plant Species. USDA Forest Service, Hilo, Hawai‘i. (In press).

Stoddart, D. R./Taylor, J. D., eds. 1971. Geography and ecology of Diego Garcia Atoll, Chagos Archipelago. Atoll Research Bulletin No. 149. Smithsonian Institution, Washington. 237 pp.

Stone, Benjamin C. 1970. The flora of Guam. Micronesica 6:1-659.

Thaman, R. R. 1987. Plants of Kiribati: a listing and analysis of vernacular names. Atoll Res. Bull. 296:1-42.

U.S. Dept. Agr., Agr. Res. Serv. 2009. National Genetic Resources Program. Germplasm Resources Information Network (GRIN). Online searchable database.

Vander Velde, Nancy. 0. Nancy Vander Velde, pers. com.

Vander Velde, Nancy. 2003. The vascular plants of Majuro Atoll, Republic of the Marshall Islands. Smithsonian Institution, Atoll Research Bulletin No. 503:1-141.

Vander Velde, Nancy/Vander Velde, Brian. 2006. Plants of Kili Island, Marshall Islands. Unpublished checklist. 12 pp.

Vander Velde, Nancy/Vander Velde, Brian. 2007. Arno plants [preliminary working listing of plant species]. Unpublished checklist, 13 pp.

Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. 1999. Manual of the flowering plants of Hawaii. Revised edition. Bernice P. Bishop Museum special publication. University of Hawai‘i Press/Bishop Museum Press, Honolulu. 1919 pp. (two volumes).

Waterhouse, D. F. 1997. The major invertebrate pests and weeds of agriculture and plantation forestry in the Southern and Western Pacific. The Australian Centre for International Agricultural Research, Canberra. 93 pp.

Welsh, S. L. 1998. Flora Societensis: A summary revision of the flowering plants of the Society Islands. E.P.S. Inc., Orem, Utah. 420 pp.

Whistler, W. A. 1983. The flora and vegetation of Swains Island. Atoll Research Bulletin No. 262. Smithsonian Institution, Washington. 25 pp.

Whistler, W. A. 1990. Ethnobotany of the Cook Islands: The plants, their Maori names, and their uses. Allertonia 5(4):347-424.

Whistler, W. A. 1992. Flora of Tonga [unpublished checklist]. 107 pp.

Whistler, W. A./Steele, O. 1999. Botanical survey of the United States of America Kwajalein Atoll (USAKA) Islands. Prepared for Oak Ridge Institute for Science and Education and the U. S. Army Environmental Center. 111 pp.

Yuncker, T. G. 1959. Plants of Tonga. Bishop Museum Bull. 220. Bishop Museum Press, Honolulu. 343 pp.