Echinochloa stagnina (Retz.) P. Beauv., Poaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Risk assessment results:  Evaluate, score: 4 (Go to the risk assessment)

Other Latin names:  Panicum stagninum Retz.

Common name(s): [more details]

English: barnyard grass, burgu grass, hippo grass, long-awn water grass

Fijian: bangara gaddi

Habit:  grass

Description: 

Genus: "Annuals or perennials, coarse, often succulent grasses with compressed sheaths and linear, flat leaf blades; panicle somewhat compressed, made up of short, densely flowered racemes borne along a main axis; spikelets solitary or in irregular clusters along one side of raceme, subsessile, often stiffly hispid, the lower glume about half length of spikelet, pointed, the upper glume and sterile lemma often bearing a long awn, enclosing a membranous palea and sometimes also the male flower, the fertile lemma smooth, shiny, the lower margins inrolled, the apex not enclosed."  (Smith, 1979)

Species:  Annual, the culms erect, 60-120 cm high; leaf blades 15-45 cm long, 5-10 mm broad; panicle erect, the racemes ascending or appressed, 1.8-5 cm long; spikelets purplish-tinged, pubescent, 3-5 mm long, the awns 1-4 mm long"  (Smith, 1979; p. 340).

"Robust perennial, aquatic grass which floats in deep water or creeps with rhizomes and stolons, to 2 m long (reported up to 8 m long); readily roots and sprouts at nodes.  Stems terete, pith-filled, buoyant.  Leaf sheaths to 15 cm long; ligule a dense fringe of hairs 1.25-3 mm long; blades linear, acuminate, 6-45 cm - 5-15 mm with a rough margin and broad pale midrib.  Inflorescence a terminal panicle to 25 cm long, comprising 5-30 pseudospikes turned to one side, on a main axis 5-30 cm long."  (Waterhouse & Mitchell, 1998; pp. 71-72).

Description from GrassBase.

Habitat/ecology:  "Swamps, river banks, rice paddies, dams, and moist disturbed sites.  Major constituent of floating swamp vegetation in Papua New Guinea." (Waterhouse & Mitchell, 1998; pp. 71-72).  In Fiji, "naturalized and fairly common" on Viti Levu (Smith, 1979; p. 340).  In Hawai‘i, "adventive in wet sites on O‘ahu" (Wagner et al., 1999; p. 1535).  In Samoa, "uncommon in wet areas" (Whistler, 1988; p. 52).

Propagation:  Seeds and stem fragments dispersed by water and birds (Waterhouse & Mitchell, 1998; pp. 71-72).

Native range:  "Tropical Asia and Africa, but now widespread" (Smith, 1979; p. 340).

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	Viti Levu Island	introduced invasive	Smith, Albert C. (1979) (p. 340) Vouchers cited: DA 2805, Greenwood 973, DA 8635, DA 10559, DA 11443, DA 3091, DA 7872, DA 8404, DA 9116, DA 3971, DA 3558, DA 8599, DA 8611, DA1247, DA 7598
Papua New Guinea Papua New Guinea (eastern New Guinea Island)	Papua New Guinea (eastern New Guinea Island)	introduced invasive	Waterhouse, B. M./Mitchell, A. A. (1998) (pp. 71-72) Sandaun, Sepik and Western Provinces.
Papua New Guinea Papua New Guinea (eastern New Guinea Island)	Papua New Guinea (eastern New Guinea Island)		Henty, E. E. (1969) (p. 84) In the Sepik and Western Districts,in permanent swamps and channels, where it is a major constituent of the floating swamp vegetation.
Philippines Philippine Islands	Philippine Islands	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Samoa Western Samoa Islands	Western Samoa Islands		Whistler, W. A. (1988) (p. 52)
Solomon Islands Solomon Islands	Solomon Islands		Swarbrick, John T. (1997) (p. 91)

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Cambodia Cambodia	Cambodia (Kingdom of)		Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 134)
Indonesia Indonesia	Indonesia (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Thailand Thailand	Thailand (Kingdom of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Vietnam Vietnam	Vietnam (Socialist Republic of)		Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 134)

Control:  If you know of control methods for Echinochloa stagnina, please let us know.