Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Risk assessment results:  Reject, score: 7 (Go to the risk assessment).

Common name(s): [more details]

Chinese: mao zhou suo cao

English: fuzzy flat sedge

Habit:  sedge

Description:  "Annual or short-lived perennial; rhizome stoloniferous, the stolons slender, elongated, soft, distantly clothed with pale brown scales; culms solitary or few together, erect, 25-85 cm tall, acutely triquetrous, 0.3-0.5 cm broad, smooth or scabrid on angles below corymb; leaves few to several to a culm, shorter than culm; blades broadly linear, flattish, 6-8 mm broad, rather soft; sheaths short, pale greenish to pale brownish, withering without disintegrating into fibers; corymbs ample, compound to decompound, with 3-10 rays of unequal length; rays patent, thickish, 2-14 cm long; secondary corymbs with 2-5 raylets 0.5-2 cm long; spikes subpyramidal, subdense, 2-3 cm long, 1-2 cm broad, the rhachis subdensely hirsute with yellow-brown short hairs; spikelets spreading, linear-lanceolate, 5-15 mm long, 1.5-2.5 mm broad, slightly swollen, 8-25-flowered, straw-colored and tinged with red-brown; rhachilla without wings; glumes subloosely disposed, broadly deltoid-ovate, acute at the often mucronulate apex, 1.8-2.2 mm long, thin-chartaceous to membranous, pale straw-colored and tinged or flecked with reddish brown, whitish-hyaline on margins, rather distinctly 5- or 7-nerved; achenes broadly elliptic to obovate, 3-sided, 1/2 to 2/3 as long as glume, dark brown at maturity; stigmas 3; style short; stamens 3"  (Smith, 1979; pp. 248-249).

Habitat/ecology:  "In Fiji it is a naturalized adventive, occurring near sea level along roadsides, in swamps and wet places along rivers, and in coconut plantations, pastures, cane fields and rice fields."  (Smith, 1979; pp. 248-249)  In Samoa, "uncommon on roadsides and in pastures" (Whistler, 1988; p. 42).

Propagation:  Seed

Native range:  Tropical West Africa through central Asia and India to Japan, eastward to Malesia and northern Australia (Smith, 1979; pp. 248-249).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Fiji Fiji Islands	Taveuni Island	introduced invasive	Smith, Albert C. (1979) (pp. 248-249) Voucher cited: DA 8890
Fiji Fiji Islands	Viti Levu Island	introduced invasive	Smith, Albert C. (1979) (pp. 248-249) Vouchers cited: DA 8634, DA 11449, DA 9439, DA 10809, DA 10015, DA 7622, DA 7403, DA 8379, DA 8615, DA 10616, DA 10576
French Polynesia Marquesas Islands	Nuku Hiva (Nukahiva) Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (2004) (voucher ID: PTBG 42495) Taxon name on voucher: Cyperus pilosus
State of Hawaii Hawaiian Islands	Kaua‘i Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1399) Single collection in 1916. "It is uncertain if this species persists in Hawai'i." (Wagner et al., 1999). Voucher cited: Forbes 481.K (BISH)
Japan (offshore islands) Bonin (Ogasawara) Islands	Bonin (Ogasawara) Islands		Kato, Hidetoshi (2007)
Palau Palau (main island group)	Babeldaob Island	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 68)
Palau Palau (main island group)	Koror Island	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 68)
Philippines Philippine Islands	Philippine Islands		Waterhouse, D. F. (1993) (p. 64)
Samoa Western Samoa Islands	Western Samoa Islands		Whistler, W. A. (1988) (p. 42) Uncommon.

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	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Australia Australia (continental)	Queensland	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Cambodia Cambodia	Cambodia (Kingdom of)		Waterhouse, D. F. (1993) (p. 64)
China China	China (People's Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
China China	Hong Kong	native	Wu, Te-lin (2001) (pp. 310-311) In marshes, paddy fields an other wet places.
Indonesia Indonesia	Indonesia (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Japan Japan	Japan (country)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Japan Ryukyu Islands	Ryukyu Islands	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Malaysia Malaysia	Malaysia (country of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Singapore Singapore	Singapore (Republic of)		Waterhouse, D. F. (1993) (p. 64)
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	Taiwan Island	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Thailand Thailand	Thailand (Kingdom of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Vietnam Vietnam	Vietnam (Socialist Republic of)		Waterhouse, D. F. (1993) (p. 64)

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

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

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

References:

Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. 2009. A checklist of the total vascular plant flora of Singapore: native, naturalised and cultivated species. Raffles Museum of Biodiversity Research, National University of Singapore. 273 pp.

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

Kato, Hidetoshi. 2007. Herbarium records of Makino Herbarium, Tokyo Metropolitan University. Personal communication.

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

Swarbrick, John T. 1997. Weeds of the Pacific Islands. Technical paper no. 209. South Pacific Commission, Noumea, New Caledonia. 124 pp.

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

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. 1993. The major arthropod pests and weeds of agriculture in Southeast Asia. The Australian Centre for International Agricultural Research, Canberra. 141 pp.

Whistler, W. A. 1988. Checklist of the weed flora of western Polynesia. Technical Paper No. 194, South Pacific Commission, Noumea, New Caledonia. 69 pp.

Wu, Te-lin. 2001. Check List of Hong Kong Plants. Hong Kong Herbarium and the South China Institute of Botany. Agriculture, Fisheries and Conservation Department Bulletin 1 (revised). 384 pp.

Zhengyi, Wu/Raven, Peter H./Deyuan, Hong. 2011. Flora of China (online resource).