Cyperus sphacelatus Rottb., Cyperaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Common name(s): [more details]

English: roadside flatsedge

Habit:  sedge

Description:  "Herbs, annual or perennial, cespitose. Culms trigonous, 15-60 cm x 1-3 mm, glabrous. Leaves 2-6, flat to V-shaped, 6-30(-40) cm x 2-4 mm. Inflorescences: spikes broadly ellipsoid, 5-45 x 10-30(-45) mm; rays (2-)5-9, (0.3-)3-10 cm; rachis 4-17 mm; bracts 5-6, horizontal to ascending, V-shaped, 1.5-30 cm x 0.5-4 mm; rachilla persistent, wings hyaline, 0.4-0.5 mm wide. Spikelets 5-30, pale greenish white or stramineous, compressed, linear-lanceoloid, 7-35 x (1.2-)1.4-2 mm; floral scales deciduous, 6-34, spreading or appressed, laterally greenish white, often reddish or brown speckled, medially green, laterally 3-5-ribbed, medially 3-ribbed, elliptic, (2.2-)3-4(-4.4) x (1.2-)1.8-2.2 mm, apex acute. Flowers: anthers 0.6 mm; styles 0.6-1.2 mm; stigmas 1-1.4(-1.7) mm. Achenes reddish brown to dark brown, stipitate, narrowly ellipsoid, 1.4-2 x 0.6-0.9 mm, apex apiculate, surfaces puncticulate"  (Flora of North America online).

Habitat/ecology:  In North America, disturbed, wet soils at low elevations  (Flora of North America online).

Propagation:  Seed

Native range:  Central and South America, central and southern Africa, Madagascar (GRIN).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
French Polynesia Marquesas Islands	Nuku Hiva (Nukahiva) Island	introduced invasive	Lorence, David H./Wagner, Warren L. (2008) Voucher cited: W.L. Wagner, D.H. Lorence, J. Florence, S.P. Perlman 6109 (BISH, US)
French Polynesia Marquesas Islands	Nuku Hiva (Nukahiva) Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Adventice
French Polynesia Society Islands	Moorea Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Adventice
French Polynesia Society Islands	Raiatea (Havai) Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Voucher cited: J. Florence & P. Birnbaum 9949 (PAP) Adventice
French Polynesia Society Islands	Tahiti Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Voucher cited: P. Morat 6392 (PAP) Adventice
French Polynesia Austral (Tubuai) Islands	Rurutu Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Voucher cited: J. Florence 9183 (PAP) Adventice. Bord de piste ensoleillé. Paraît d'introduction récente.
State of Hawaii Hawaiian Islands	Moloka‘i Island	introduced invasive	Oppenheimer, Hank (2008) (p. 27) Vouchers cited: Oppenheimer et al. H50643 (BISH, PTBG), Oppenheimer H110739 (BISH, PTBG)
Papua New Guinea Papua New Guinea (eastern New Guinea Island)	Papua New Guinea (eastern New Guinea Island)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2011)

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	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Colombia Colombia	Colombia (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Costa Rica Costa Rica	Costa Rica (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Ecuador (Mainland) Ecuador	Ecuador (Republic of) (continental)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Indonesia Indonesia	Indonesia (Republic of)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Japan Japan	Japan (country)	introduced	Mito, Toshikazu/Uesugi, Tetsuro (2004) (p. 193)
Malaysia Malaysia	Malaysia (country of)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Nicaragua Nicaragua	Nicaragua (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Panama Panama	Panama (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Perú Perú	Perú (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Thailand Thailand	Thailand (Kingdom of)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Vietnam Vietnam	Vietnam (Socialist Republic of)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2011)

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)	USA (Florida)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2011)

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

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

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

References:

Flora of North America Editorial Committee, eds. 2011. Flora of North America North of Mexico (online edition).

Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. 2011. Base de données botaniques Nadeaud de l'Herbier de la Polynésie Française (PAP). (online resource).

Lorence, David H./Wagner, Warren L. 2008. Flora of the Marquesas Islands. National Tropical Botanical Garden and the Smithsonian Institution. Online database.

Mito, Toshikazu/Uesugi, Tetsuro. 2004. Invasive alien species in Japan: the status quo and the new regulation for prevention of their adverse effects. Global Environmental Research 8(2)/2004: 171-191.

Oppenheimer, Hank. 2008. New Hawaiian plant records for 2007. In: Evenhuis, Neal L. and Eldredge, Lucias G., eds. Records of the Hawaii Biological Survey for 2007. Bishop Museum Occasional Papers 100:22-38.

U. S. Government. 2011. Integrated Taxonomic Information System (ITIS) (on-line resource).

U.S. Dept. Agr., Agr. Res. Serv. 2011. National Genetic Resources Program. Germplasm Resources Information Network (GRIN). Online searchable database.