Ottelia alismoides (L.) Pers., Hydrocharitaceae

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Present on Pacific Islands?  no

Primarily a threat at high elevations?  no

Other Latin names:  Stratiotes alismoides L.

Common name(s): [more details]

Chinese: long she cao

English: duck lettuce, water plantain ottelia

Habit:  aquatic herb

Description: 

Genus:  "Attached, submerged or emergent freshwater herbs.  Leaves radical, petiole base sheathing.  Spathe with prominent ribs or wings, peduncled, 1-flowered; flowers bisexual in Australian species, sessile within spathe, conspicuous in Australian species; sepals 3, persistent; petals 3, longer than sepals; stamens 6-15, 6-12 in Australian species; styles 6-15, 6-9 in Australian species, bifid.  Fruits with thickened pericarp."

Key to Australian species:

Otellia alismoides:  Leaf blades submerged, broadly ovate to suborbicular, thin and translucent; spathe with 5-10 conspicuous longitudinal wings, sometimes wings reduced to ribs.
Otellia ovalifolia:  Leaf blades floating on water surface, elliptic to ovate, thick and opaque; spathe ribbed but without wings.

Species:  "Leaves submerged, sometimes partly emergent in shallow water; petioles 3-sided, 8-50 cm long; blades thin, translucent, broadly ovate to suborbicular, 7-22 cm x 4.5-21 cm.  Spathes 2.5-6 cm long with 5-10 longitudinal wings; sepals 1-1.5 cm long; petals white with yellow-spotted base, 2-3 cm long.  Fruits enclosed in spathe; seeds glabrous"  (Stanley & Ross, 1989; vol. 3, p. 10).

Habitat/ecology:  In Australia, "in slow moving streams and stagnant pools up to 1.5 m deep, on a muddy bottom" (Stanley & Ross, 1989; vol. 3, p. 10).

Propagation:  Seed

Native range:  Africa, India, southwest Pacific (Hickman, 1993; p. 1151).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Philippines Philippine Islands	Philippine Islands		Waterhouse, D. F. (1993) (p. 67)
Solomon Islands Solomon Islands	Solomon Islands	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Solomon Islands Solomon Islands	Solomon Islands	native	Hancock, I. R./Henderson, C. P. (1988) (p. 95)

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)	Northern Territory	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Australia Australia (continental)	Queensland	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Cambodia Cambodia	Cambodia (Kingdom of)		Waterhouse, D. F. (1993) (p. 67)
Central America Central America (Pacific rim)	Honduras (Republic of)		Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 258)
China China	China (People's Republic of)		Hafliger, E. (1092) (p. 93)
Indonesia Indonesia	Indonesia (Republic of)		Waterhouse, D. F. (1993) (p. 67)
South Korea South Korea	South Korea (Republic of)		Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 258)
Malaysia Malaysia	Malaysia (country of)		Waterhouse, D. F. (1993) (p. 67)
Singapore Singapore	Singapore (Republic of)	introduced cultivated	Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. (2009) (p. 65) Cultivated only
Taiwan Taiwan Island	Taiwan Island		Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 258)
Thailand Thailand	Thailand (Kingdom of)		Waterhouse, D. F. (1993) (p. 67)
Vietnam Vietnam	Vietnam (Socialist Republic of)		Waterhouse, D. F. (1993) (p. 67)

Control:  If you know of control methods for Ottelia alismoides, please let us know.