Eragrostis japonica (Thunb.) Trin., Poaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Other Latin names:  Eragrostis elegans Nees; Eragrostis glomerata (Walter) L. H. Dewey; Eragrostis tenellula (Kunth) Steud.; Poa japonica Thunb.

Common name(s): [more details]

Chinese: luan cao

English: Japanese lovegrass, pond lovegrass

Japanese: kogome-kaze-kusa

Habit:  grass

Description:  "Caespitose annuals. Culms 25-100 (115) cm tall, erect, sometimes geniculate below, branching from the lower and middle nodes, glabrous and somewhat shiny below the nodes.  Sheaths overlapping below, about 3/4 to 7/8 as long as the internodes above, glabrous at the summit and along the upper margins.  Ligules 0.4-0.6 mm long, a delicate membrane, glabrous.  Blades (4) 15-20 (25) cm long, 1.5-6 mm wide, flat, glabrous below and scaberulous above, sometimes auriculate near the base.  Panicle 15-40 cm long, 0.8-5 cm wide, condensed, lanceolate, interrupted below, the ascending, often appressed branches 2-10 cm long, spreading up to 30§ from the culm axis, the branches scaberulous and shiny, floriferous near base; pulvini in the axils of the primary branches glabrous; pedicels 0.5-1.5 mm long, erect and sinuous.  Spikelets 2.2-3.8 mm long, 0.8-1.3 mm wide, 4-12-flowered, oblong to narrowly lanceolate, compressed, yellowish-brown to somewhat whitish and hyaline; disarticulation between the florets, the portion of the rachilla and floret falling as a unit.  Glumes 0.6-1 mm long, ovate to ovate-lanceolate, subequal, faintly keeled, scaberulous along the keel,, hyaline, 1-nerved or the first often without a nerve.  Lemmas 0.9-1.2 mm long, ovate, hyaline, the lateral nerves conspicuous below, greenish, keeled, glabrous along the keel, apex acute.  Paleas 0.6-0.8 mm long, bowed out, hyaline, scaberulous along the keel near the apex, apex acute, often bifid.  Stamens 2, anthers 0.1-0.2 mm long, whitish to light brown.  Caryopses 0.3-0.4 mm long, obovoid, smooth, reddish-brown" (Lægaard & Peterson, 2001; p. 39).

Description from GrassBase.

Habitat/ecology:  In Ecuador, "occurs in moist areas along rivers and streams, usually in sandy soils below 100 m" (Lægaard & Peterson, 2001; p. 39).

Propagation:  Seed

Native range:  Tropical and subtropical Africa and Asia; exact native range obscure (GRIN).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Papua New Guinea Papua New Guinea (eastern New Guinea Island)	Papua New Guinea (eastern New Guinea Island)		Henty, E. E. (1969) (p. 93) A weed of gardens, nursery beds, etc.
Philippines Philippine Islands	Philippine Islands		Waterhouse, D. F. (1993) (p. 65)
Philippines Philippine Islands	Philippine Islands		Merrill, Elmer D. (1925) (pp. 89-90) In open wet grasslands, along streams, etc., at low and medium altitudes.
Solomon Islands Solomon Islands	Solomon Islands	native	Hancock, I. R./Henderson, C. P. (1988) (p. 71)

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	National Herbarium of New South Wales (2013) As Eragrostis tenellula (Kunth) Steud.
Australia Australia (continental)	Australia (continental)	native	National Herbarium of New South Wales (2013) As Eragrostis tenellula (Kunth) Steud. South Australia, Western Australia
Australia Australia (continental)	Queensland	native	National Herbarium of New South Wales (2013) As Eragrostis tenellula (Kunth) Steud.
Cambodia Cambodia	Cambodia (Kingdom of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Central America Central America (Pacific rim)	Costa Rica (Republic of)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Natualized
Central America Central America (Pacific rim)	El Salvador (Republic of)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Natualized
Central America Central America (Pacific rim)	Guatemala (Republic of)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Natualized
Central America Central America (Pacific rim)	Honduras (Republic of)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Natualized
China China	China (People's Republic of)	native	Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2013) Fields, roadsides, stream banks. Anhui, Fujian, Guangdong, Guangxi, Guizhou, Henan, Hubei, Jiangsu, Jiangxi, Yunnan, Zhejiang.
China China	Hong Kong	native	Wu, Te-lin (2001) (p. 335) In farmland and other wet places.
Indonesia Indonesia	Indonesia (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Japan Japan	Japan	native	U.S. Dept. Agr., Agr. Res. Serv. (2013) Honshu, Kyushu, Shikoku
Japan Ryukyu Islands	Ryukyu Islands	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Malaysia Malaysia	Malaysia (country of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Mexico Mexico	Mexico (United Mexican States)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Natualized
South America (Pacific rim) South America (Pacific rim)	Ecuador (Republic of) (continental)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Natualized
South America (Pacific rim) South America (Pacific rim)	Perú (Republic of)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Natualized
Taiwan Taiwan Island	Taiwan Island	native	Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2013) Fields, roadsides, stream banks.
Thailand Thailand	Thailand (Kingdom of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Vietnam Vietnam	Vietnam (Socialist Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)

Also reported from
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
United States (continental except west coast) United States (other states)	United States (other states)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Natualized
United States (continental except west coast) United States (other states)	USA (Florida)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Natualized

Control:  If you know of control methods for Eragrostis japonica, please let us know.