Pacific Island Ecosystems at Risk (PIER)

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Pistia stratiotes
L., Araceae
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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Risk assessment results:  Reject, score: 18 (Go to the risk assessment)

Common name(s): [more details]

Chinese: da piao

English: Nile cabbage, tropical duckweed, water cabbage, water lettuce, water lily

French: laitue d'eau, pistie

Spanish: flor de tetumo, lechuga de agua, lechuguilla, lechuguita de agua, repollito de agua, repollo de sapo, verdolago de agua

Habit:  aquatic herb

Description:  "Aquatic, floating, rosette-forming stemless stoloniferous herbs, with sessile, obovate or obcuneate glaucous (water-shedding) leavesSpathe small, the limb ovate, enclosing one gynoecium; anthers 4, sessile, connate, in a spathe.  Fruits membranous, few-seeded, the seeds obovoid-oblong" (Stone, 1970). "[A] free-floating but soon stoloniferous, small, aquatic, perennial plant, with a tuft of long, very fibrous roots beneath, primary roots 2 to 7 mm in diameter and 1 m long, very fine, plumosely spreading root hairs; leaves obovate-cuneat, erect, few to many, 2.5 to 15 cm long, the basal part somewhat velvety-hairy, becoming thickened by the production of very porous tissue except when stranded on banks; flowers bisexual; bracts (spathes) subtending flowers; spathes white, densely dotted when dry, finely hairy (pilose) outside, smooth inside, 7 to 12 mm long, 5 mm wide, short-penduncled in the center of the rosette of leaves; spadix bearing the individual flowers is shorter than the spathe, flowering parts minute; fruit berrylike (baccate), rupturing irregularly, seeds usually numerous, oblong, tapering toward the base, the apex appearing as if cut off at the end, about 2 mm long.  The light yellow-green leaves in the form of a rosette (cabbage-like) which are velvety-hairy and prominently veined below are characteristic of this species" (Holm et al., 1977; p. 379).

Habitat/ecology:  "The free-floating plants are found in reservoirs, ponds, and marshes along the edges of large tropical lakes where they are able to thrive amidst the offshore vegetation and debris; in slow-moving or stagnant waters; and in old wells" (Holm et al., 1977; p. 379).  "It is a common floating plant in dams, lagoons, lakes and also grows in wetland rice. It is also found floating on stagnant water and sometimes rooting on muddy banks.  Like Water hyacinth this plant also blocks irrigation canals and provides a breeding ground for mosquitoes and choking fishery waters" (Ecoport).  In Hawai‘i, "occurs in open ditches, ponds, and other watercourses, generally at low elevations"  (Wagner et al., 1999; p. 1359). In New Caledonia, "pante aquatique cultivée dans des bassins artificiels et parfois spontanée" (MacKee, 1994; p. 18).

Propagation:  "This aquatic plant usually propagates by means of stolons which break easily from the plant accounts. Reproduction also takes place by seeds" (Ecoport).

Native range:  Unknown, now pan-tropical. A common aquatic weed in hot climatic countries.

Presence:

Pacific
Country/Terr./St. &
Island group
Location Cited status &
Cited as invasive &
Cited as cultivated &
Cited as aboriginal introduction?
Reference &
Comments
Commonwealth of the Northern Mariana Islands (US)
Northern Mariana Islands
Rota Island introduced
Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 93)
Cook Islands
Southern Cook Islands
Rarotonga Island introduced
Sykes, Bill (year unknown)
Federated States of Micronesia
Kosrae Island
Kosrae Island introduced
cultivated
Lorence, David H./Flynn, Timothy (2010) (p. 6)
"Potentially invasive"
French Polynesia
Society Islands
Tahiti Island introduced
Fosberg, F. R. (1997) (p. 10)
French Polynesia
Society Islands
Tahiti Island introduced
invasive
Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013)
Voucher cited: J. Florence 4621 (PAP)
Naturalisée
French Polynesia
Society Islands
Tahiti Island   Bishop Museum (Honolulu) (1983) (voucher ID: BISH 554434)
Taxon name on voucher: Pistia stratiotes L.
Guam
Guam Island
Guam Island introduced
invasive
Stone, Benjamin C. (1970) (pp. 123-124)
Voucher cited: Stone & Cushing-Falanruw 8234 (GUAM)
Guam
Guam Island
Guam Island introduced
Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 93)
State of Hawaii
Hawaiian Islands
Hawai‘i (Big) Island introduced
invasive
Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1359)
State of Hawaii
Hawaiian Islands
Kaua‘i Island introduced
invasive
Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1359)
State of Hawaii
Hawaiian Islands
Maui Island introduced
invasive
Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1359)
State of Hawaii
Hawaiian Islands
O‘ahu Island introduced
invasive
Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1359)
New Caledonia
New Caledonia Archipelago
Île Grande Terre introduced
invasive
cultivated
MacKee, H. S. (1994) (p. 18)
Vouchers cited: MacKee 40825, Suprin in MacKee 45680, Jérémie & Tirel 1654
Palau
Palau (Belau ) (main island group)
Babeldaob Island introduced
cultivated
Space, James C./Lorence, David H./LaRosa, Anne Marie (2009) (p. 5)
Seen in cultivation, source unknown.
Papua New Guinea
Bougainville Islands
Bougainville Island   Foreman, D. B. (1971) (p. 23)
Papua New Guinea
Papua New Guinea (eastern New Guinea Island)
Papua New Guinea (eastern New Guinea Island)   Waterhouse, D. F. (1997) (p. 64)
Philippines
Philippine Islands
Philippine Islands introduced
invasive
Waterhouse, D. F. (1993) (pp. 68, 78)
Philippines
Philippine Islands
Philippine Islands   Merrill, Elmer D. (1925) (p. 189)
Floating in shallow water of lakes and slow streamsat low altitudes; often abundant.
Solomon Islands
Solomon Islands
Solomon Islands   Swarbrick, John T. (1997) (p. 95)
Solomon Islands
Solomon Islands
Solomon Islands native
Hancock, I. R./Henderson, C. P. (1988) (p. 100)
Vanuatu
New Hebrides Islands
Vanuatu (Republic of) introduced
invasive
Shine, C./Reaser, J. K./Gutierrez, A. T., eds. (2003) (p. 179)
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   Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 381)
Australia
Australia (continental)
Queensland   Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 381)
Cambodia
Cambodia
Cambodia (Kingdom of) introduced
invasive
Waterhouse, D. F. (1993) (pp. 68, 78)
Central America
Central America (Pacific rim)
El Salvador (Republic of)   Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (pp. 381-384)
Central America
Central America (Pacific rim)
Honduras (Republic of)   Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (pp. 381-384)
Central America
Central America (Pacific rim)
Nicaragua (Republic of)   Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (pp. 381-384)
China
China
China (People's Republic of) introduced
invasive
Li-ying, Li/Ren, Wang/Waterhouse, D. F. (1997) (p. 174)
China
China
Hong Kong native
Wu, Te-lin (2001) (p. 300)
Prefer hot, humid environment, in ponds and ditches.
Indonesia
Indonesia
Indonesia (Republic of) introduced
invasive
Waterhouse, D. F. (1993) (pp. 68, 78)
Japan
Japan
Japan (country) introduced
Mito, Toshikazu/Uesugi, Tetsuro (2004) (p. 193)
Malaysia
Malaysia
Malaysia (country of) introduced
invasive
Waterhouse, D. F. (1993) (pp. 68, 78)
Negara Brunei Darussalam
Brunei
Brunei (Negara Brunei Darussalam) introduced
invasive
Waterhouse, D. F. (1993) (pp. 68, 78)
New Zealand
New Zealand
New Zealand (country) introduced
invasive
Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (pp. 379-384)
Singapore
Singapore
Singapore (Republic of) introduced
invasive
Waterhouse, D. F. (1993) (pp. 68, 78)
Singapore
Singapore
Singapore (Republic of) introduced
invasive
Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. (2009) (p. 70)
Naturalised
South America (Pacific rim)
South America (Pacific rim)
Colombia (Republic of)   Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 381)
Taiwan
Taiwan Island
Taiwan Island introduced
invasive
Li-ying, Li/Ren, Wang/Waterhouse, D. F. (1997) (p. 174)
Thailand
Thailand
Thailand (Kingdom of) introduced
invasive
Waterhouse, D. F. (1993) (pp. 68, 78)
United States (west coast)
United States (west coast states)
USA (California)   U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)
Vietnam
Vietnam
Vietnam (Socialist Republic of) introduced
invasive
Waterhouse, D. F. (1993) (pp. 68, 78)
Indian Ocean
Country/Terr./St. &
Island group
Location Cited status &
Cited as invasive &
Cited as cultivated &
Cited as aboriginal introduction?
Reference &
Comments
La Réunion (France)
La Réunion Island
La Réunion Island introduced
invasive
cultivated
Lavergne, Christophe (2006)
"Cultivé/±envahissant"
Seychelles
Seychelles Islands
Seychelles Islands introduced
Weber, Ewald (2003) (p. 332)
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)   U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)
United States (continental except west coast)
United States (other states)
USA (Florida)   U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)

Comments:  A Class A (eradicate) noxious weed in New Zealand.

Planting of this species in the State of Florida (U.S.) is prohibited by Florida Department of Environmental Protection (Hunsberger, 2001).

Control: 

Biological: "The curculionid weevil Neohydronomous pulchellus [affinis], which was collected in South America substantially reduced growth of Pistia stratiotes in Australia and Zimbabwe. This is the most sustainable method to control this free floating weed" (GPPIS). 

"The host specific South American weevil, Neohydronomus affinis, has been established readily in six countries and, in all, has produced substantial to excellent control.  The moth, Samea multiplicalis, which attacks P. stratiotes and Salvinia spp., has been established in Australia but its impact has not been evaluated.  In Thailand, classical biological control has not been attempted, but mass rearing and release of the native noctuid moth Spodoptera pectinicornis has replaced the use of herbicides.  The prospects are excellent for classical biological control of P. stratiotes in countries where it is still regarded as an important weed." (Waterhouse, 1994; pp. 196-207).

Waterhouse (1994, pp. 199-207) lists natural enemies and summarizes attempts at biological control.

Biological control information from the publication "Biological control of invasive plants in the eastern United States".


Need more info? Have questions? Comments? Information to contribute? Contact PIER! (pier@hear.org)

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This page was created on 1 JAN 1999 and was last updated on 12 APR 2013.