Eriochloa polystachya Kunth, Poaceae

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Present on Pacific Islands?  no

Primarily a threat at high elevations?  no

Other Latin names:  Eriochloa subglabra (Nash) Hitchc.; Monachne subglabra Nash

Common name(s): [more details]

English: Carib grass, Caribbean cup grass

Habit:  grass

Description:  "Aquatic perennial, creeping grass 5-150 cm tall.  Stems terete or slightly compressed with a central air cavity.  Leaf sheaths ribbed, apically keeled; nodes densely and finely hairy; ligule a fringe of hairs; leaf blade linear, 6-25 cm - 6-15 mm, flat, with an acute apex and scabrous margins.  Inflorescence an erect terminal panicle, 12-24 cm long, with 6-15 pseudo-spikes.  Lower pseudo-spikes 6-15 cm long, shortening upwards to 2.5-4 cm long.  Spikelets hairy, 2-3.8 mm long, with a marked basal swelling; flowers 1 or 2; spikelets shed as a whole when mature."  (Waterhouse & Mitchell, 1998; pp. 73-74).

Description from GrassBase.

Habitat/ecology:  "Swamps, deep-water rice fields, river banks, drains and ditches on heavy soils. Tolerates strong to medium dry seasons. Rear of coastal dunes to 500 m altitude. Noxious in deeply inundated rice fields where dense growth suppresses other vegetation." (Waterhouse & Mitchell, 1998; pp. 73-74).

Propagation:  "Seeds (where produced) and vegetative fragments dispersed by water" (Waterhouse & Mitchell, 1998; pp. 73-74).

Native range:  Tropical America (Waterhouse & Mitchell, 1998; pp. 73-74).

Presence:

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
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)
Honduras Honduras	Honduras (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Indonesia Indonesia	Indonesia (Republic of)		Waterhouse, B. M./Mitchell, A. A. (1998) (p. 74) Java, Tanimbar Island
Mexico Mexico	Mexico (United Mexican States)	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)		Waterhouse, B. M./Mitchell, A. A. (1998) (p. 74)
Vietnam Vietnam	Vietnam (Socialist Republic of)		Waterhouse, B. M./Mitchell, A. A. (1998) (p. 74)

Comments:  "A serious weed in Mexico" (Waterhouse & Mitchell, 1998; pp. 73-74).

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

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

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

References:

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

Waterhouse, B. M./Mitchell, A. A. 1998. Northern Australia Quarantine Strategy: weeds target list. Second edition. Australian Quarantine & Inspection Service, Miscellaneous Publication No. 6/98. 110 pp.