Cyperus gracilis R.Br., Cyperaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Common name(s): [more details]

English: McCoy grass, slender sedge, whisker grass

Hawaiian: mau‘u hunehune

Habit:  sedge

Description:  "Perennials, rhizomes short, covered with brown fibers; culms slender, 10-35 cm tall, 0.2-0.5 mm in diameter, somewhat thickened at base.  Leaves 2-3 per culm, blades linear-filiform, 1/3-1/2 as long as the culm, 0.5-1 mm wide, channeled, apex long-acuminate; sheaths brown.  Inflorescence a digitate head of 2-6 spikelets; involucral bracts 2-3, filiform, 3-10 cm long, reflexed; spikelets 8-24-flowred, pale green, linear-oblong, flattened, 5-12 mm long, ca. 2 mm wide, subacute, rachilla not winged; glumes closely spaced, broadly ovate, 2-2.3 mm long, 1.8-2 mm wide, margins hyaline, pale green and sometimes tinged yellowish brown, finely 3-7-nerved, apex acute, the keel green, prominent, ending in a short recurved mucro; style filiform; stigmas 3.  Achenes brownish black at maturity, obdeltoid-obovoid, ca. 1 mm long, trigonous, apex subtruncate, apiculate, base stipitate"  (Wagner et al., 1999; p. 1396).

Habitat/ecology:  In Hawai‘i, "cultivated as a ground cover in shaded sites and sparingly naturalized, 0-170 m" (Wagner et al., 1999; p. 1396).  "Uncommon in disturbed places" (Whistler, 1988; p. 41).

Propagation:  Seed

Native range:  Australia and New Caledonia in wet, partially shaded areas (Wagner et al., 1999; p. 1396).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Australia (Pacific offshore islands) Norfolk Islands	Norfolk Island	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Australia (Pacific offshore islands) Norfolk Islands	Norfolk Island	introduced invasive	Orchard, Anthony E., ed. (1994) (p. 11) "Rare. Probably a recent introduction". Vouchers cited: W.R. Sykes NI 468(CHR), K.L. Wilson 6261 (K, NSW)
State of Hawaii Hawaiian Islands	Hawai‘i (Big) Island	introduced invasive	Starr, Forest/Starr, Kim/Loope, Lloyd L. (2003) (p. 27) Voucher cited: Starr & Martz 010801-12 (BISH)
State of Hawaii Hawaiian Islands	Kaho‘olawe Island	introduced invasive	Starr, Forest/Starr, Kim (2011) (p. 25) Voucher cited: Starr, Starr & Higashino 080209-01 (BISH)
State of Hawaii Hawaiian Islands	Kaua‘i Island	introduced invasive cultivated	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 1396-1397)
State of Hawaii Hawaiian Islands	Lāna‘i Island	introduced invasive	Oppenheimer, Hank L./Bartlett, Randal T. (2002) (p. 7) Voucher cited: Oppenheimer H109912 (BISH)
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive cultivated	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 1396-1397)
State of Hawaii Hawaiian Islands	Moloka‘i Island	introduced invasive cultivated	Hughes, Guy D'Oyly (1995) (p. 3) Voucher cited: Hughes 13 (US) Common in lawns, along roadsides, and in disturbed areas.
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced invasive cultivated	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 1396-1397)
New Caledonia New Caledonia	New Caledonia Islands	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
New Caledonia New Caledonia Archipelago	Île Grande Terre	native	MacKee, H. S. (1994) (p. 144) Vouchers cited: MacKee 26176, MacKee 43724
Niue Niue	Niue Island	introduced	Whistler, W. A. (1988) (p. 41)
Tonga Tongatapu Group	Tongatapu Island		Whistler, W. A. (1988) (p. 41)

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. (2013)
Australia Australia (continental)	Australia (continental)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013) Victoria
Australia Australia (continental)	Queensland	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
United States (west coast) United States (west coast states)	USA (California)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Naturalized

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