Pacific Island Ecosystems at Risk (PIER)

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Imperata conferta
(J.Presl) Ohwi, Poaceae
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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Other Latin names:  Imperata exaltata auct.; Saccharum confertum J. Presl

Common name(s): [more details]

English: plume grass

Fijian: gi, ngi

Habit:  grass

Description: 

Genus:  "Rhizome subterranean; flowering culms of few internodes, tall; leaf-blades nearly all arising from near the base of the culm, very long, erect; inflorescence a much branched panicle, its branches ascending close to the main axis, the whole compact and cylindric at flowering; branchlets not jointed, spikelets paired or solitary, all alike, bisexual, if paired pedicels unequal, and bearing a few long fine hairs near the thickened top and many fine spreading white hairs also on the base of the spikelets, hairs twice as long as the glumes or more; glumes about equal, hairy on the back, thin; lower floret neuter, lemma much smaller than the glumes, no palea; upper floret hermaphrodite, lemma thin, not awned, palea present."

Key to species of Imperata:

Imperata cylindrica:  Stamens 2.  Panicle up to 30 x 2 cm.
Imperata conferta:  Stamen 1.  Panicle up to 50 x 5 cm.

Species:  "As in [Imperata cylindrica], similarly rhizomatous and spreading, nodes glabrous or short-hairy, a larger plant but with smaller flowers.  Leaf-sheaths loose, 12.5 cm or longer; blades narrowing to each end, acuminate, less scabrid on the margins, up to 45.0 x 1.4 cm; ligule membranous, nearly glabrous.  Inflorescence a strict but more open panicle, up to 50 cm long by 5 cm across, the lowest branches to 12 cm long, ultimately capillary, with the spikelets mainly in pairs, one long pedicelled, 2.6 mm and one short pedicelled, 1.2 mm; spikelets all alike, callus furnished with long silky hairs 2.2 cm long, lower glume 3 mm long, delicate 3-nerved, lanceolate-acuminate; upper glume likewise, 2.8 mm long; lower lemma 1-nerved, narrowly linear-acuminate; upper glume likewise, 2.8 mm long; lower lemma 1-nerved, narrowly linear-acuminate, delicately hyaline, 2 mm long; palea nil; upper lemma delicately hyaline, 1-nerved and denticulate, 2 mm long; palea delicately hyaline, wrapped around the stamen and pistil, 1.2 mm long; stamen 1, anthers 2 mm long; stigmata plumose, purplish" (Gilliland, 1971; pp. 220-221).

Description from GrassBase.

Habitat/ecology:  In Fiji, "common from sea level to about 900 m, occurring on hillsides, along streams and trails in dense or open forest, on damp slopes, along roadsides, and on coconut plantations" (Smith, 1979; pp. 365-366).  "Common in Samoa on high-elevation lava flows, elsewhere uncommon in sunny, disturbed places" (Whistler, 1988; p. 53). In New Guinea, "from sea level to 3000 m" (Henty & Pritchard, 1975; p. 42).

Propagation:  Seed

Native range:  Southeastern Asia and Malesia (Smith, 1979; pp. 365-366).

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   National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (1991) (voucher ID: PTBG 9504)
Taxon name on voucher: Imperata conferta
Commonwealth of the Northern Mariana Islands (US)
Northern Mariana Islands
Rota Island introduced
Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 44)
Commonwealth of the Northern Mariana Islands (US)
Northern Mariana Islands
Saipan Island introduced
Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 44)
Commonwealth of the Northern Mariana Islands (US)
Northern Mariana Islands
Saipan Island introduced
Fosberg, F. R./Sachet, M.-H. (1982) (pp. 49-50)
Voucher cited: Herbst & Falanruw 6894 (US)
Commonwealth of the Northern Mariana Islands (US)
Northern Mariana Islands
Tinian Island introduced
Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 44)
Commonwealth of the Northern Mariana Islands (US)
Northern Mariana Islands
Tinian Island introduced
Fosberg, F. R./Sachet, M.-H. (1982) (pp. 49-50)
Vouchers cited: Fosberg 59882 (US, BISH), Herbst & Falanruw 6807 (US)
Federated States of Micronesia
Yap Islands
Yap (Waqab) Island introduced
Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 44)
Federated States of Micronesia
Yap Islands
Yap (Waqab) Island possibly native
Fosberg, F. R./Sachet, M.-H. (1982) (pp. 49-50)
Vouchers cited: Takamatsu 1925 (US, POM, BISH), Takematsu 1901 (US, POM, BISH), Cushing 378 (US)
Fiji
Fiji Islands
Kandavu Island introduced
invasive
Smith, Albert C. (1979) (pp. 365-366)
Voucher cited: DA 9080
Fiji
Fiji Islands
Koro Island introduced
invasive
Smith, Albert C. (1979) (pp. 365-366)
Fiji
Fiji Islands
Lakemba Island introduced
invasive
Smith, Albert C. (1979) (pp. 365-366)
Fiji
Fiji Islands
Matuku Island introduced
invasive
Smith, Albert C. (1979) (pp. 365-366)
Fiji
Fiji Islands
Moala Island introduced
invasive
Smith, Albert C. (1979) (pp. 365-366)
Fiji
Fiji Islands
Moturiki Island introduced
invasive
Smith, Albert C. (1979) (pp. 365-366)
Fiji
Fiji Islands
Ngau Island introduced
invasive
Smith, Albert C. (1979) (pp. 365-366)
Fiji
Fiji Islands
Ovalau Island introduced
invasive
Smith, Albert C. (1979) (pp. 365-366)
Fiji
Fiji Islands
Taveuni Island introduced
invasive
Smith, Albert C. (1979) (pp. 365-366)
Vouchers cited: Gillespie 4714, DA 8911
Fiji
Fiji Islands
Vanua Levu Island introduced
invasive
Smith, Albert C. (1979) (pp. 365-366)
Vouchers cited: DA 8762, DA 8787, DA 8868, Degener & Ordonez 14204, DA 16875
Fiji
Fiji Islands
Viti Levu Island introduced
invasive
Smith, Albert C. (1979) (pp. 365-366)
Vouchers cited: DA 11335, Degener & Ordonez 13572, DA 2093, DA 9030, Smith 9485, DA 8624, Smith 8769, DA 7308, Gillespie 3163.5, DA 3981, DA 1206, DA 9328, C.R. Turbet 33
Fiji
Fiji Islands
Wakaya Island introduced
invasive
Smith, Albert C. (1979) (pp. 365-366)
Guam
Guam Island
Guam Island introduced
Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 44)
Guam
Guam Island
Guam Island introduced
Fosberg, F. R./Sachet, M.-H. (1982) (pp. 49-50)
Vouchers cited: Fosberg 59648 (US, BISH, POM, MO, K, BRI), P. H. Moore 889 (US, GUAM), Falanruw 956 (US), Stone 4717 (GUAM)
New Caledonia
New Caledonia
New Caledonia Islands   Swarbrick, John T. (1997) (p. 93)
New Guinea (Indonesia and Papua New Guinea)
New Guinea Island
New Guinea Island native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Palau
Palau (Belau ) (main island group)
Angaur (Ngeaur) Island introduced
Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 44)
Palau
Palau (Belau ) (main island group)
Angaur (Ngeaur) Island introduced
invasive
Space, James C./Waterhouse, Barbara/Miles, Joel E./Tiobech, Joseph/Rengulbai, Kashgar (2003) (p. 103)
Palau
Palau (Belau ) (main island group)
Angaur (Ngeaur) Island possibly native
Fosberg, F. R./Sachet, M.-H. (1982) (pp. 49-50)
Voucher cited: Canfield 190 (US)
Palau
Palau (Belau ) (main island group)
Babeldaob Island introduced
Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 44)
Palau
Palau (Belau ) (main island group)
Babeldaob Island introduced
invasive
Space, James C./Waterhouse, Barbara/Miles, Joel E./Tiobech, Joseph/Rengulbai, Kashgar (2003) (p. 101)
Palau
Palau (Belau ) (main island group)
Babeldaob Island possibly native
Fosberg, F. R./Sachet, M.-H. (1982) (pp. 49-50)
Vouchers cited: Tuyama i 1937 (TI, in part), Kanehira & Hatusima 4551 (FU), Hosaka 3386 (BISH, US, K), Timberlake 3144 (US)
Palau
Palau (Belau ) (main island group)
Babeldaob Island introduced
invasive
Space, James C./Lorence, David H./LaRosa, Anne Marie (2009) (p. 60)
Voucher: Lorence 9810 (PTBG)
Palau
Palau (Belau ) (main island group)
Babeldaob Island   Beleu National Museum (Republic of Palau. Koror.) (1981) (voucher ID: BNM 3144)
Taxon name on voucher: Imperata conferta (Presl.) Ohwi
Palau
Palau (Belau ) (main island group)
Babeldaob Island   National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (2008) (voucher ID: PTBG 49591)
Taxon name on voucher: Imperata conferta (Presl) Ohwi
Palau
Palau (Belau ) (main island group)
Koror (Oreor) Island introduced
Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 44)
Palau
Palau (Belau ) (main island group)
Koror (Oreor) Island possibly native
Fosberg, F. R./Sachet, M.-H. (1982) (pp. 49-50)
Voucher cited: Fosberg 37079 (US, BISH)
Palau
Palau (Belau ) (main island group)
Peleliu (Beliliou) Island introduced
invasive
Space, James C./Waterhouse, Barbara/Miles, Joel E./Tiobech, Joseph/Rengulbai, Kashgar (2003) (p. 106)
Palau
Rock Islands (Chelbacheb)
Aulupse‘el (Ulebsechel) Island introduced
Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 44)
Palau
Rock Islands (Chelbacheb)
Aulupse‘el (Ulebsechel) Island possibly native
Fosberg, F. R./Sachet, M.-H. (1982) (pp. 49-50)
Voucher cited: Fosberg 32362 (US)
Papua New Guinea
Papua New Guinea (eastern New Guinea Island)
Papua New Guinea (eastern New Guinea Island) invasive
Henty, E. E. (1969) (p. 111)
Commmon in grassland, becoming dominant on deeper, more fertile or recently disturbed soil.
Papua New Guinea
Papua New Guinea (eastern New Guinea Island)
Papua New Guinea (eastern New Guinea Island) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Philippines
Philippine Islands
Philippine Islands native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Philippines
Philippine Islands
Philippine Islands   Merrill, Elmer D. (1925) (p. 31)
As Imperata exaltata Brongn.
Samoa
Western Samoa Islands
Upolu Island   National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (1989) (voucher ID: PTBG 4070)
Taxon name on voucher: Imperata conferta
Samoa
Western Samoa Islands
Western Samoa Islands   Whistler, W. A. (1988) (p. 53)
Solomon Islands
Solomon Islands
Solomon Islands   Swarbrick, John T. (1997) (p. 93)
Tonga
Ha‘apai Group
Kao Island possibly introduced
Whistler, W. A. (1992) (p. 99)
Vouchers cited: Yuncker 15918, Yuncker 15936
Tonga
Ha‘apai Group
Kao Island   Yuncker, T. G. (1959) (p. 64)
As Imperata cylindrica; vouchers cited: Yuncker 15918, Yuncker 15936
Tonga
Ha‘apai Group
Tofua Island possibly introduced
Whistler, W. A. (1992) (p. 99)
Vouchers cited: Hotta 4426, Scarth-Johnson 110
Tonga
Tongatapu Group
‘Eua Island possibly introduced
Whistler, W. A. (1992) (p. 99)
Vouchers cited: Parks 16239, Yuncker 15457, Sykes 332a, Sykes 669, Whistler 7407
Tonga
Tongatapu Group
‘Eua Island   Yuncker, T. G. (1959) (p. 64)
As Imperata cylindrica; voucher cited: Yuncker 15457
Tonga
Vava‘u Group
Late Island introduced
Sykes, W. R. (1981) (p. 352)
Tonga
Vava‘u Group
Late Island possibly introduced
Whistler, W. A. (1992) (p. 99)
Vouchers cited: Hotta 4450! (cf. 4456), Hotta 4459!, Buelow & Sykes 93
Tonga
Vava‘u Group
Tafahi Island possibly introduced
Whistler, W. A. (1992) (p. 99)
Voucher cited: Whistler 6289
Vanuatu
New Hebrides Islands
Vanuatu (Republic of)   Swarbrick, John T. (1997) (p. 93)
Wallis and Futuna
Wallis and Futuna (Horne) Islands
Wallis and Futuna Islands   Whistler, W. A. (1988) (p. 53)
Pacific Rim
Country/Terr./St. &
Island group
Location Cited status &
Cited as invasive &
Cited as cultivated &
Cited as aboriginal introduction?
Reference &
Comments
Indonesia
Indonesia
Indonesia (Republic of) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Java
Malaysia
Malaysia
Malaysia (country of) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Singapore
Singapore
Singapore (Republic of) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Singapore
Singapore
Singapore (Republic of) native
Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. (2009) (p. 50)
Common
Thailand
Thailand
Thailand (Kingdom of) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)


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This page was created on 8 SEP 2002 and was last updated on 2 JAN 2013.