Vallisneria spiralis L., Hydrocharitaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Common name(s): [more details]

English: coiled vallisneria, eelgrass, eelweed, ribbon weed, tape grass, tape weed

French: vallisnerie en spirale

Habit:  aquatic herb

Description:  "An annual or a perennial, submersed, stoliniferous, dioecious plant with stems buried in mud; roots fibrous; leaves ribbon-like, sheathing base, arranged in tufts at intervals along a stolon, 1 to 7 cm broad, 1 to 6 m long, upper portion sometimes floating at the surface, 5 to 9 main longitudinal veins with fine transverse connections, acute to obtuse, edges may be finely toothed toward apex, winged at base with one wing folded over edge of next inner leaf and other wing extended; pistillate flower 1.5 to 2.5 cm long, solitary, sessile, within membranous sheath, peduncle may be up to 60 cm long as flower bud is raised to surface; spathe 1.5 to 2 cm long; sepals 3, concave, springing directly from summit of the ovary; petals 3, white, alternate with sepals, minute and scarcely visible; pistil with 3, 2-lobed nearly sessile stigmas; ovary inferior, long, cylindrical, unilocular, with mucilage-filled cavity containing numerous crowded ovules; staminate flower minute, less than 1 mm long and broad, numerous, enclosed by membranous spathe; spathe 1 to 2 cm long, terminal on a 7 cm long peduncle; perianth of 3 sepals, concave, 2 larger than the third; stamens usually 3; petals absent; fruit long, 4 mm broad, many seeds embedded in a gelatinous mass, enveloped by the persistent spathe; seed tapering, ellipsoidal, papillate, 1.5 to 3 mm long"  (Holm et al., 1997; p. 897).

Habitat/ecology:  "It is most often found in 0.5 to 3 m of water (reported to 10 m in clear water).  It is found in lakes, rivers, waterlogged swamps with open water, man-made reservoirs, and irrigation channels.  It thrives in streams but is seldom present in fast water"  (Holm et al., 1997; pp. 895, 897).

Propagation:  "Seed, winter buds, or fragments of rootstocks.  Depending on the site, season and region, one or more of the propagules may be important for this widely distributed weed"  (Holm et al., 1997; p. 898).

Native range:  India, Malaysia and Australia (GRIN).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced invasive cultivated	Staples, George W./Imada, Clyde T./Herbst, Derral R. (2003) (p. 13) Vouchers cited: C. Imada, L. Roth, C.N. Lee 2000-1 (BISH), R. Englund s.n. (BISH 666333), C. Imada & D. Preston 2001-25 (BISH), C. Imada & D. Preston 2001-26 (BISH), C. Imada, R. Englund & D. PReston 2001-44 (BISH) Locally naturalized and abundant.
New Caledonia New Caledonia Archipelago	Île Grande Terre	introduced cultivated	MacKee, H. S. (1994) (p. 66) Vouchers cited: Bougier s.n. s. loc, MacKee 43535
Papua New Guinea Papua New Guinea (eastern New Guinea Island)	Papua New Guinea (eastern New Guinea Island)		Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 895)
Philippines Philippine Islands	Philippine Islands	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Philippines Philippine Islands	Philippine Islands		Merrill, Elmer D. (1925) (p. 26) In lakes and slow streams at low altitudes.

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	U.S. Dept. Agr., Agr. Res. Serv. (2013)
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)
China China	China (People's Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Indonesia Indonesia	Indonesia (Republic of)		Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 895)
Japan Japan	Japan	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Japan Japan	Japan	introduced	Mito, Toshikazu/Uesugi, Tetsuro (2004) (p. 191)
South Korea South Korea	South Korea (Republic of)		Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 895)
Malaysia Malaysia	Malaysia (country of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
New Zealand New Zealand	New Zealand (country)	introduced invasive	Healy, A. J./Edgar, E. (1980) (p. 26)
South America (Pacific rim) South America (Pacific rim)	Colombia		Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 895)
Taiwan Taiwan Island	Taiwan Island		Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 895)
Thailand Thailand	Thailand (Kingdom of)		Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 895)
Vietnam Vietnam	Vietnam (Socialist Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)

Control:  If you know of control methods for Vallisneria spiralis, please let us know.