Pacific Island Ecosystems at Risk (PIER)

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Polygonum aviculare
L., Polygonaceae
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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  yes

Common name(s): [more details]

Chinese: bian xu

English: doorweed, hogweed, ironweed, knotgrass, knotweed, prostrate knotweed, wireweed, yard knotweed

French: centinode, herbe aux cochons, renouée des oiseaux, trainasse

Japanese: michi-yanagi, niwayanagi

Spanish: alambrillo, caminadora, centinodia, cien nudos, coloradilla, corredora, correguela de los caminos, gonorrea, herbe de las calenturas, hierba de chivo, huichun, huichuri, lengue de pajaro, pasto del pollo, sangrina, sanguinaria, sanguinaria mayor, verdolaga

Habit:  herb

Description:  "Glabrous, taprooted annual or short-lived perennial herbs; stems usually prostrate and often rooting at the nodes, or erect with ascending lateral branches.  Leaves few to numerous, widely spaced to crowded, linear to narrowly oblong or narrowly elliptic, (0.2-) 0.3-1.5 (-2.5) cm long, 0.1-0.6 cm wide, petioles short, jointed to the blade, ocreae hyaline, laciniate, 5-10 mm long.  Flowers 1-3, axillary, pedicels filiform, shorter than the ocreae so that the flower and fruit are erect; tepals green, apex whitish tinged reddish purple, sometimes not opening and perhaps the flower cleistogamous, 3 tepals arranged over the angle of the nut and the inner 2 on the nut faces.  Nuts dark brown, trigonous, ca. 2-3 mm long, the surface minutely papillose, appearing striate, dull"  (Wagner et al., 1999; p. 1063).

Habitat/ecology:  "A common weed in trampled areas such as footpaths and animal trails, in lawns, along the edges and in cracks of sidewalks and other paved surfaces, along roadsides, and especially in fields of cereal crops.  It is found on dark and sandy loam soils rich in N but also grows well on infertile soil.  It grows in soils with pHs of 5.6 to 8.4.  A variable species with many growth forms and varieties.  In full sunlight, plants remain prostrate and can form dense mats of wiry stems or the main stem remains flat and the branches may be somewhat erect.  In partial shade, it is nearly erect, reaching 30 to 40 cm tall.  It invades bare ground and competes well with grasses"  (Holm et al., 1997; p. 598).

In Hawai‘i, "sparingly naturalized in pastures and other disturbed areas, 1,000-2,080 m"  (Wagner et al., 1999; p. 1063).

Propagation:  Seed, dispersed by birds, mammals and water (Weber, 2003; p. 339).

Native range:  "Widespread in temperate regions of the world, perhaps native to Europe"  (Wagner et al., 1999; p. 1063).

Presence:

Pacific
Country/Terr./St. &
Island group
Location Cited status &
Cited as invasive &
Cited as cultivated &
Cited as aboriginal introduction?
Reference &
Comments
Chile (offshore islands)
Juan Fernández Islands
Isla Más a Tierra (Robinson Crusoe Island) introduced
Skottsberg, Carl (1953) (p. 216)
Chile (offshore islands)
Juan Fernández Islands
Isla Más a Tierra (Robinson Crusoe Island) introduced
invasive
Atkinson, Rachel/Sawyer, John (2011)
Chile (offshore islands)
Juan Fernández Islands
Isla Más a Tierra (Robinson Crusoe Island) introduced
invasive
Danton, Philippe/Perrier, Christophe/Martinez Reyes, Guido (2006) (p. 556)
Chile (offshore islands)
Juan Fernández Islands
Isla Más Afuera (Alejandro Selkirk Island) introduced
invasive
Atkinson, Rachel/Sawyer, John (2011)
Chile (offshore islands)
Juan Fernández Islands
Isla Más Afuera (Alejandro Selkirk Island) introduced
invasive
Danton, Philippe/Perrier, Christophe/Martinez Reyes, Guido (2006) (p. 556)
State of Hawaii
Hawaiian Islands
Hawai‘i (Big) Island introduced
invasive
Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1063)
Voucher cited: Ewart III 196 (BISH)
State of Hawaii
Hawaiian Islands
Maui Island introduced
invasive
Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1063)
New Zealand (offshore islands)
Kermadec Islands
Kermadec Islands introduced
invasive
Webb, C. J./Sykes, W. R./Garnock-Jones, P. J. (1988) (p. 971)
"Cultivated ground, waste places, railway tracks, roadsides and other modified habitats, also poor and open pastures and riverbeds".
Casual
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)
Australia (continental)   Hafliger, Toni J./Wolf, Matthias (1988) (p. 279)
Australia
Australia (continental)
New South Wales   Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 596)
Australia
Australia (continental)
Northern Territory   Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 596)
Australia
Australia (continental)
Queensland   Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 596)
Chile (continental)
Chile
Chile (Republic of) introduced
invasive
Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 596)
China
China
China (People's Republic of) invasive
Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2013)
"Near fields, roadsides, waste places; sea level to 4200 m".
China
China
China (People's Republic of)   Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 596)
Colombia
Colombia
Colombia (Republic of) introduced
invasive
Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 596)
Ecuador (Mainland)
Ecuador
Ecuador (Republic of) (continental) introduced
invasive
Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 596)
El Salvador
El Salvador
El Salvador (Republic of)   Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 287)
Guatemala
Guatemala
Guatemala (Republic of) introduced
invasive
Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 596)
Honduras
Honduras
Honduras (Republic of) introduced
invasive
Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 596)
Japan
Japan
Japan (country)   Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 596)
Japan
Japan
Japan (country) introduced
Mito, Toshikazu/Uesugi, Tetsuro (2004) (p. 181)
var. condensatum Beck. and var. monospeliensie Thiband.
South Korea
South Korea
South Korea (Republic of)   Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 596)
Mexico
Mexico
Mexico (United Mexican States) introduced
invasive
Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 596)
New Zealand
New Zealand
New Zealand (country) introduced
invasive
Webb, C. J./Sykes, W. R./Garnock-Jones, P. J. (1988) (p. 971)
"Cultivated ground, waste places, railway tracks, roadsides and other modified habitats, also poor and open pastures and riverbeds".
Perú
Perú
Perú (Republic of) introduced
invasive
Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 596)

Control:  "Specific control methods for this species are not available.  Plants may be cut before fruit formation to prevent seed dispersal.  Seedlings can be hand pulled, larger plants treated with herbicide"  (Weber, 2003; p. 339).


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This page was created on 24 JAN 2007 and was last updated on 20 JAN 2011.