Sonchus oleraceus L., Asteraceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Other Latin names:  Sonchus asper sensu various authors.

Common name(s): [more details]

Bontoc: gagatang

English: annual milk thistle, annual sow thistle, common sow thistle, hare's-lettuce, milk thistle, sow thistle

Fijian: thandavu

French: laiteron commun, laiteron potager, lastron piquant, polais de lièvre

Hawaiian: pualele

Japanese: nogeshe

Mangarevan: retero, taru

Maori (Cook Islands): pū‘ā, pu‘ā, puā

Niuean: puha, pupu lele

Spanish: cerraja, cerrajilla, llisco, morraja, nilhue

Tongan: longolongo‘uha

Habit:  herb

Description:  "An erect, soft, simple or branched, taprooted, annual or sometimes biennial herb; stem smooth, pale bluish green or powdery, sometimes purplish, 30 to 120 cm tall, with milky juice; basal and lower leaves stalked, up to 20 cm long, 3 to 6 cm wide, basal leaves originally rosetted, upper leaves sessile and clasping the stem, the leaves divided into broad toothed and spiny segments with the terminal segments being the largest and triangular, and being green on both sides, sometimes tinged with purple; flowering heads numerous, pale yellow, 2 to 3 cm broad, with smooth involucre; seeds (achene) 2 to 3 mm long, broadest toward the top, tapering to a narrow base, ribbed lengthwise, and transversely wrinkled by the presence of minute warty lumps (tubercles); pappus of numerous silky hairs about 1.5 cm long.  The plant may be distinguished by its toothed leaves, hollow stems, and milky sap.  It has a fibrous taproot" (Holm et al., 1977; p. 436).

"Annual or longer-lived herb, to 50 (-100) cm high, unbranched or with a few branches, glabrous or nearly so, stems often hollow; leaves at base oblong-oblanceolate, pinnately parted, spine-toothed, 15-50 cm long, 5-8 cm wide; middle and upper leaves sessile, basal ones with winged petiole; heads about 2 cm wide; corolla about 1 cm long; achenes slender obovate, about 2.5-3 mm long, transversely scabrously ribbed; pappus about 6-6.5 mm long"  (Stone, 1970; p. 578).

Habitat/ecology:  "The weed is adapted to a number of environments and grows well at low and high elevations in the tropics.  It is usually found in moist conditions in fields, orchards, roadsides, gardens, or waste areas.  It often occurs in irrigated lands" (Holm et al., 1977; p. 438).  "Forests, grassland, riparian habitats, freshwater wetlands, coastal estuaries and dunes.  This widespread weed is invasive in natural habitats because it grows in dense patches that crowd out native plants.  It is a shade intolerant pioneer species establishing in disturbed sites.  The plant's large size and its high nutrient uptake may result in impoverishment of heavily infested sites"  (Weber, 2003; p. 413).

In Hawai‘i, "naturalized in a variety of disturbed habitats" (Wagner et al., 1999; p. 358).  In Guam, occasional but ephemeral in moist waste ground (Stone, 1970; p. 578).  In Fiji, "naturalized as a weed in clearings and cultivated areas and along forest trails from near sea level to about 900 m"  (Smith, 1991; pp. 265-266).  In Niue, "a common weed in plantations and sometimes in waste places" (Sykes, 1970; p. 68).  "Occasional in disturbed areas" (Whistler, 1988; p. 12). Arid lowlands in the Galápagos Islands; a common weed of disturbed areas such as roadsides and gardens (McMullen, 1999; 197). In New Guinea, "a weed of gardens and field crops; relished by livestock. Sporadic at altitudes from 1000 to 2500 m." (Henty & Pritchard, 1975; p. 79). In New Caledonia, "cité (MacGillivray, 1854) comme mauvaise herbe partout à l'Ile des Pins en 1854. La note de Vieillar & Deplance (1863); "Les néo-calédoniens font un grande usage des feuilles de Sonchus laevis Camer." s'appliquerait probablement à cetter espèce" (MacKee, 1994; p. 38).

Propagation:  "The plant reproduces by seeds that are produced in large quantities and are carried by wind or water" (Holm et al., 1977; p. 436).

Native range:  Europe (Wagner et al., 1999; p. 358). Eurasia and northern Africa (Smith, 1991; pp. 265-266).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Australia (Pacific offshore islands) Lord Howe Island	Lord Howe Island	introduced invasive	Orchard, Anthony E., ed. (1994) (p. 18) "A common weed of disturbed soil". Vouchers cited: P.S. Green 1628 (A, K), J. Pickard 2880 (NSW), J. Pickard 2903 (NSW), J.D. McComish 201 (NSW)
Australia (Pacific offshore islands) Norfolk Islands	Norfolk Island	introduced invasive	Orchard, Anthony E., ed. (1994) (p. 8) "A common weed of disturbed soil". Voucher cited: G. Uhe 1131 (K)
Chile (offshore islands) Rapa Nui (Easter) Island	Rapa Nui (Easter) Island (Isla de Pasqua)	introduced	Skottsberg, Carl (1953) (p. 81) Summit of Rano Kao, but scattered examples everywhere on the island.
Chile (offshore islands) Juan Fernández Islands	Isla Más a Tierra (Robinson Crusoe Island)	introduced	Skottsberg, Carl (1953) (p. 227)
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. 558)
Chile (offshore islands) Juan Fernández Islands	Isla Más Afuera (Alejandro Selkirk Island)	introduced	Skottsberg, Carl (1953) (p. 227)
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. 558)
Chile (offshore islands) Juan Fernández Islands	Isla Santa Clara	introduced	Skottsberg, Carl (1953) (p. 227)
Chile (offshore islands) Juan Fernández Islands	Isla Santa Clara	introduced invasive	Atkinson, Rachel/Sawyer, John (2011)
Chile (offshore islands) Juan Fernández Islands	Isla Santa Clara	introduced invasive	Danton, Philippe/Perrier, Christophe/Martinez Reyes, Guido (2006) (p. 558)
Chile (offshore islands) Juan Fernández Islands	Morro El Verdugo	introduced invasive	Danton, Philippe/Perrier, Christophe/Martinez Reyes, Guido (2006) (p. 558)
Chile (offshore islands) Juan Fernández Islands	Morro Juanango	introduced invasive	Danton, Philippe/Perrier, Christophe/Martinez Reyes, Guido (2006) (p. 558)
Cook Islands Southern Cook Islands	Aitutaki Atoll		McCormack, Gerald (2011)
Cook Islands Southern Cook Islands	‘Atiu Island		McCormack, Gerald (2011)
Cook Islands Southern Cook Islands	Mangaia Island		McCormack, Gerald (2011)
Cook Islands Southern Cook Islands	Ma‘uke Island		McCormack, Gerald (2011)
Cook Islands Southern Cook Islands	Miti‘aro Island		McCormack, Gerald (2011)
Cook Islands Southern Cook Islands	Rarotonga Island		McCormack, Gerald (2011)
Ecuador (Galápagos Islands) Fernandina Group	Fernandina Island	introduced invasive	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) Floreana Group	Floreana Island	introduced invasive	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) Isabela Group	Isabela Island	introduced invasive	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) Isabela Group	Volcán Alcedo, Isabela Island	introduced invasive	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) Isabela Group	Volcán Cerro Azul, Isabela Island	introduced invasive	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) Isabela Group	Volcán Darwin, Isabela Island	introduced invasive	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) Isabela Group	Volcán Ecuador, Isabela Island	introduced invasive	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) Isabela Group	Volcán Sierra Negra, Isabela Island	introduced invasive	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) Isabela Group	Volcán Wolf, Isabela Island	introduced invasive	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) San Cristóbal Group	San Cristóbal Island	introduced invasive	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) Santa Cruz Group	Santa Cruz Island	introduced invasive	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) Santiago Group	Santiago Island	introduced invasive	Charles Darwin Foundation (2008)
Federated States of Micronesia Pohnpei Islands	Pohnpei Island		Glassman, S. F. (1952) (p. 97) Voucher cited: Glassman 2581 (US)
Federated States of Micronesia Pohnpei Islands	Pohnpei Island	introduced invasive	Herrera, Katherine/Lorence, David H./Flynn, Timothy/Balick, Michael J. (2010) (p. 73) Naturalized
Fiji Fiji Islands	Kandavu Island	introduced invasive	Smith, Albert C. (1991) (pp. 265-266) Voucher cited: Smith 302
Fiji Fiji Islands	Lakemba Island	introduced invasive	Smith, Albert C. (1991) (pp. 265-266) Voucher cited: Garnock-Jones 902
Fiji Fiji Islands	Matuku Island	introduced invasive	Smith, Albert C. (1991) (pp. 265-266) Voucher cited: Milne 116
Fiji Fiji Islands	Viti Levu Island	introduced invasive	Smith, Albert C. (1991) (pp. 265-266) Vouchers cited: Greenwood 179, Gillespie 4166, DA 9773, DA 11694, Seemann 266, Simmonds s. n.
French Polynesia French Polynesia Islands	French Polynesia Islands		Waterhouse, D. F. (1997) (p. 65)
French Polynesia Gambier Islands	Akamaru Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Adventice
French Polynesia Gambier Islands	Akamaru Island	introduced	St. John, Harold (1988) (p. 26) Voucher cited: St. John 14711 (BISH)
French Polynesia Gambier Islands	Mangareva (Gambier) Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Adventice
French Polynesia Gambier Islands	Mangareva (Gambier) Island	introduced	St. John, Harold (1988) (p. 26) Vouchers cited: Agassiz 130 (GH), St. John 14543 (BISH), Fosberg 11041 (BISH), Fosberg 11042
French Polynesia Marquesas Islands	Eiao Island	introduced invasive	Lorence, David H./Wagner, Warren L. (2008)
French Polynesia Marquesas Islands	Eiao Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Vouchers cited: J. Florence & M. Teikiteetini 9321 (PAP), J. Florence & M. Teikiteetini 9373 (PAP), J.-C. Thibault 1035 (PAP) Adventice
French Polynesia Marquesas Islands	Fatu Hiva Island	introduced invasive	Lorence, David H./Wagner, Warren L. (2008)
French Polynesia Marquesas Islands	Fatu Hiva Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Voucher cited: J. Florence, D.H. Lorence & W.L. Wagner 9469 (PAP) Adventice
French Polynesia Marquesas Islands	Hiva Oa Island	introduced invasive	Lorence, David H./Wagner, Warren L. (2008)
French Polynesia Marquesas Islands	Hiva Oa Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Voucher cited: M.-H. Sachet, R.L. Oliver & P.A. Schäfer 2135 (PAP) Adventice
French Polynesia Marquesas Islands	Hiva Oa Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (1963) (voucher ID: PTBG 45105) Taxon name on voucher: Sonchus oleraceus
French Polynesia Marquesas Islands	Mohotani (Mohotane, Mohotane) Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Adventice
French Polynesia Marquesas Islands	Nuku Hiva (Nukahiva) Island	introduced invasive	Lorence, David H./Wagner, Warren L. (2008)
French Polynesia Marquesas Islands	Nuku Hiva (Nukahiva) Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Vouchers cited: J. Florence 4117 (PAP), J. Florence 6903 (PAP) Adventice
French Polynesia Marquesas Islands	Nuku Hiva (Nukahiva) Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (1964) (voucher ID: PTBG 45106) Taxon name on voucher: Sonchus oleraceus
French Polynesia Marquesas Islands	Tahuata (Tuhuata) Island	introduced invasive	Lorence, David H./Wagner, Warren L. (2008)
French Polynesia Marquesas Islands	Tahuata (Tuhuata) Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (2003) (voucher ID: PTBG 39407) Taxon name on voucher: Sonchus oleraceus
French Polynesia Marquesas Islands	Ua Huka (Huahuna, Uahuka) Island	introduced invasive	Lorence, David H./Wagner, Warren L. (2008)
French Polynesia Marquesas Islands	Ua Huka (Huahuna, Uahuka) Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (2004) (voucher ID: PTBG 42431) Taxon name on voucher: Sonchus oleraceus L.
French Polynesia Society Islands	Bora Bora Island	introduced invasive	Welsh, S. L. (1998) (p. 80) Voucher cited: Grant 4874
French Polynesia Society Islands	Mehetia (Mahetia, Meetia) Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Adventice
French Polynesia Society Islands	Moorea Island		Fosberg, F. R. (1997) (p. 19)
French Polynesia Society Islands	Moorea Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Adventice
French Polynesia Society Islands	Raiatea (Havai) Island	introduced invasive	Welsh, S. L. (1998) (p. 80) Voucher cited: Moore 379
French Polynesia Society Islands	Tahiti Island	introduced invasive	Welsh, S. L. (1998) (p. 80) Voucher cited: Grant 3569
French Polynesia Society Islands	Tahiti Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Vouchers cited: J. Florence 2531 (PAP), W.A. Whistler & M. Guérin 21 (PAP) Adventice
French Polynesia Tuamotu Archipelago	Fangatau Atoll	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Voucher cited: J.-C. Jolinon 1305 (PAP) Adventice
French Polynesia Tuamotu Archipelago	Fangataufa (Ahunui) Atoll	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Voucher cited: J.-C. Jolinon 1305 (PAP) Adventice
French Polynesia Austral (Tubuai) Islands	Raivavae (Raevavae) Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Voucher cited: J. Florence 5600 (PAP) Adventice
French Polynesia Austral (Tubuai) Islands	Rapa Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Voucher cited: J. Florence 6283 (PAP) Adventice
French Polynesia Austral (Tubuai) Islands	Rapa Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (year unknown) (voucher ID: PTBG 45112) Taxon name on voucher: Sonchus oleraceus
French Polynesia Austral (Tubuai) Islands	Rimatara (Rimitara) Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Adventice
French Polynesia Austral (Tubuai) Islands	Rurutu Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Voucher cited: J. Florence 9243 (PAP) Adventice
French Polynesia Austral (Tubuai) Islands	Tubuai Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Adventice
Guam Guam Island	Guam Island	introduced invasive	Stone, Benjamin C. (1970) (p. 578)
Guam Guam Island	Guam Island	introduced	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1979) (p. 290)
State of Hawaii Hawaiian Islands	French Frigate Shoals	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 358)
State of Hawaii Hawaiian Islands	Hawai‘i (Big) Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 358)
State of Hawaii Hawaiian Islands	Kaho‘olawe Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 358)
State of Hawaii Hawaiian Islands	Kaua‘i Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 358)
State of Hawaii Hawaiian Islands	Ka‘ula Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 358)
State of Hawaii Hawaiian Islands	Kure Atoll	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 358)
State of Hawaii Hawaiian Islands	Kure Atoll	introduced invasive	Starr, Forest/Martz, Kim/Loope, Lloyd (2001) (p. 17) Occasional in grassy open areas especially near the quarters.
State of Hawaii Hawaiian Islands	Lāna‘i Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 358)
State of Hawaii Hawaiian Islands	Ni‘ihau, Lehua Islet	introduced invasive	Wood, K. R./LeGrande, Maya (2006) (p. 21) Voucher cited: Flynn et al. 4861 (PTBG)
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 358)
State of Hawaii Hawaiian Islands	Moloka‘i Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 358)
State of Hawaii Hawaiian Islands	Nihoa Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 358)
State of Hawaii Hawaiian Islands	Ni‘ihau Island	introduced invasive	Herbarium Pacificum Staff (1996) (p. 3) Vouchers cited: J.F.G. Stokes s.n. (BISH), H. St. John 23581 (BISH)
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 358)
State of Hawaii Hawaiian Islands	Pearl and Hermes Reef	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 358)
State of Hawaii Hawaiian Islands	Pearl and Hermes Reef	introduced invasive	Starr, Forest/Martz, Kim (1999) (p. 20) Southeast Island: Occasional on east side only
State of Hawaii Hawaiian Islands	Tern Island	introduced invasive	Starr, Forest/Martz, Kim (1999) (p. 7) Occasional everywhere.
Japan (offshore islands) Bonin (Ogasawara) Islands	Bonin (Ogasawara) Islands		Kato, Hidetoshi (2007)
Japan (offshore islands) Marcus Island	Marcus Island (Minami Tori Shima)	introduced	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1979) (p. 290)
Kiribati Line Islands	Tabuaeran (Fanning) Atoll	introduced invasive	Wester, Lyndon (1985) (p. 33)
Kiribati Line Islands	Tabuaeran (Fanning) Atoll	introduced invasive	Christophersen, Erling (1927) (p. 43) Observed near the Cable Station.
Kiribati Tungaru (Gilbert) Islands	Tarawa Atoll		Swarbrick, John T. (1997) (p. 97) Presence not verified.
Marshall Islands Ralik Chain	Kwajalein (Kuwajleen) Atoll	introduced	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1979) (p. 290)
Marshall Islands Ralik Chain	Kwajalein (Kuwajleen) Atoll	introduced invasive	Whistler, W. A./Steele, O. (1999) (p. 37) Voucher cited: Fosberg 31164. Not found in this survey and may no longer be present.
Marshall Islands Ratak Chain	Arno Atoll	introduced	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1979) (p. 290)
Marshall Islands Ratak Chain	Majuro (Mãjro) Atoll	introduced	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1979) (p. 290)
New Caledonia Îles Bélep (Belep Islands)	Île Art	introduced invasive	MacKee, H. S. (1994) (p. 38) Voucher cited: MacKee 19446
New Caledonia Hunter Island	Île Hunter	introduced invasive	MacKee, H. S. (1994) (p. 38) Voucher cited: Monzier in Veillon 6941
New Caledonia Îles Loyauté (Loyalte Islands)	Îles Loyauté (Loyalty Islands)	introduced invasive	Tassin, Jacques (2005)
New Caledonia Îles Loyauté (Loyalte Islands)	Île Lifou	introduced invasive	MacKee, H. S. (1994) (p. 38) Voucher cited: MacKee 27278
New Caledonia Îles Loyauté (Loyalte Islands)	Îles Ouvéa (Ouvea Atoll)	introduced invasive	MacKee, H. S. (1994) (p. 38) Voucher cited: MacKee 18905
New Caledonia Îles Loyauté (Loyalte Islands)	Île Tiga	introduced invasive	MacKee, H. S. (1994) (p. 38) Voucher cited: MacKee 45850
New Caledonia Îles Loyauté (Loyalte Islands)	Île Walpole	introduced invasive	MacKee, H. S. (1994) (p. 38) Voucher cited: Cherrier in MacKee 43814
New Caledonia Îles Loyauté (Loyalte Islands)	Île Walpole	introduced	Renevier, Alain/Cherrier, Jean-Francois (1991) (p. 16) Voucher cited: Cherrier in MacKee 44083
New Caledonia Matthew Island	Île Matthew	introduced invasive	MacKee, H. S. (1994) (p. 38) Voucher cited: Veillon 3413 (NOU)
New Caledonia New Caledonia	New Caledonia Islands	introduced invasive	Gargominy, Oliver/Bouchet, Philipe/Pascal, Michel/Jaffre, Tanguy/Tourneu, Jean-Christophe (1996) (p. 379) Rudérale, nombreuses localités
New Caledonia New Caledonia Archipelago	Île Grande Terre	introduced invasive	Tassin, Jacques (2005)
New Caledonia New Caledonia Archipelago	Île Grande Terre	introduced invasive	MacKee, H. S. (1994) (p. 38) Vouchers cited: Balansa 19, Hoff 971 (NOU)
New Caledonia New Caledonia Archipelago	Île des Pins (Isle of Pines)	introduced invasive	Tassin, Jacques (2005)
New Caledonia New Caledonia Archipelago	Île des Pins (Isle of Pines)	introduced invasive	MacKee, H. S. (1994) (p. 38) Voucher cited: Germain s.n.
New Zealand (offshore islands) Kermadec Islands	Kermadec Islands	introduced invasive	Webb, C. J./Sykes, W. R./Garnock-Jones, P. J. (1988) (p. 344) "Waste land, grassland, coastal rocks, dunes and beaches, forest margins, crevices in walls and footpaths, gardens, pasture, roadsides, railway land&
New Zealand (offshore islands) Kermadec Islands	Raoul Island	introduced invasive	Sykes, W. R. (1977) (p. 96) "Waste land, grassland, coastal rocks, dunes and beaches, forest margins, crevices in walls and footpaths, gardens, pasture, roadsides".
Niue Niue	Niue Island	introduced invasive	Sykes, W. R. (1970) (p. 68) Voucher cited: CHR 170428
Niue Niue	Niue Island	introduced invasive	Whistler, W. A. (1988) (p. 12)
Niue Niue	Niue Island	introduced invasive	Whistler, W. A./Atherton, J. (1997) (p. 26)
Niue Niue	Niue Island	introduced invasive	Yuncker, T. G. (1943) (p. 119) Vouchers cited: Yuncker 9758 (BISH), Yuncker 9909 (BISH), Yuncker 10076 (BISH) "A common weed in waste areas and plantations".
Niue Niue	Niue Island	introduced invasive	Space, James C./Waterhouse, Barbara M./Newfield, Melanie/Bull, Cate (2004) (p. 47)
Papua New Guinea Papua New Guinea (eastern New Guinea Island)	Papua New Guinea (eastern New Guinea Island)	introduced invasive	Henty, E. E./Pritchard, G. H. (1975) (p. 79) Sporadic at altitudes from 1000 to 2500 m.
Papua New Guinea Papua New Guinea (eastern New Guinea Island)	Papua New Guinea (eastern New Guinea Island)		Waterhouse, D. F. (1997) (p. 65)
Philippines Philippine Islands	Philippine Islands	introduced invasive	Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 439)
Philippines Philippine Islands	Philippine Islands		Merrill, Elmer D. (1923) (p. 621) In waste places like Sonchus arvensis but occasional at lower altitudes.
Pitcairn Islands Pitcairn Islands	Pitcairn Island	introduced	St. John, H. (1987) (p. 54) Voucher cited: Fosberg & B. Christian 11212
Pitcairn Islands Pitcairn Islands	Pitcairn Island	introduced	Fosberg, F. R./Paulay, Gustav/Spencer, T./Oliver, Royce (1989) (p. 15) Voucher cited: Paulay, Spencer & Schuster 671 (US)
Pitcairn Islands Pitcairn Islands	Pitcairn Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Voucher cited: J. Florence 10765 (PAP) Adventice
Samoa Western Samoa Islands	Western Samoa Islands		Waterhouse, D. F. (1997) (p. 65)
Tonga Tonga Islands	Tonga Islands		Whistler, W. A. (1988) (p. 12)
Tonga Tonga Islands	Tonga Islands	introduced invasive	Yuncker, T. G. (1959) (p. 270) "Probably grows throughout Tonga".
Tonga Tongatapu Group	Tongatapu Island	introduced invasive	Yuncker, T. G. (1959) (p. 270) Voucher cited: Yuncker 16239
Tonga Tongatapu Group	Tongatapu Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (1989) (voucher ID: PTBG 3859) Taxon name on voucher: Sonchus oleraceus
Tonga Vava‘u Group	Late Island	introduced	Sykes, W. R. (1981) (p. 349)
United States (other Pacific offshore islands) Johnston Atoll	Johnston Island	introduced invasive	Amerson, A. Binion, Jr./Shelton, Philip C. (1976) (p. 60) Identification uncertain. May be Sonchus asper.
United States (other Pacific offshore islands) Johnston Atoll	Johnston Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (1965) (voucher ID: PTBG 45111) Taxon name on voucher: Sonchus oleraceus
United States (other Pacific offshore islands) Midway Atoll	Eastern Island	introduced invasive	Starr, Forest/Starr, Kim/Loope, Lloyd (2008) (pp. B-13)
United States (other Pacific offshore islands) Midway Atoll	Midway Atoll	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 358)
United States (other Pacific offshore islands) Midway Atoll	Sand Island	introduced invasive	Starr, Forest/Starr, Kim/Loope, Lloyd (2008) (pp. B-13)
United States (other Pacific offshore islands) Midway Atoll	Spit Island	introduced invasive	Starr, Forest/Starr, Kim/Loope, Lloyd (2008) (pp. B-13)
United States (other Pacific offshore islands) Wake Islands	Wake Island	introduced invasive	Fosberg, F. R. (1959) (p. 19) Voucher cited: Fosberg 34464, Fosberg 34483 Rare weed.
United States (other Pacific offshore islands) Wake Islands	Wake Island	introduced	Fosberg, F. R./Sachet, M.-H. (1969) (p. 15) Not seen in 1961 or 1963.
United States (other Pacific offshore islands) Wake Islands	Wake Island	introduced invasive	Fosberg, F. R. (1955) (p. 22) Vouchers cited: Fosberg 34464 (US), Fosberg 34483 (US)
Vanuatu New Hebrides Islands	Vanuatu (Republic of)		Swarbrick, John T. (1997) (p. 97)
Wallis and Futuna Wallis and Futuna (Horne) Islands	Wallis (‘Uvea) Island	introduced invasive	Morat, Ph./Veillon, J.-M. (1985) Morat & Veillon, 1985, cited in Meyer, 2007
Wallis and Futuna Wallis and Futuna (Horne) Islands	Wallis and Futuna Islands		Whistler, W. A. (1988) (p. 12)

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)	introduced invasive	Weber, Ewald (2003) (p. 413)
Australia Australia (continental)	Queensland	introduced invasive	Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 439)
Cambodia Cambodia	Cambodia (Kingdom of)		Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 345)
Chile (continental) Chile	Chile (Republic of)	introduced invasive	Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 439)
China China	China (People's Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Colombia Colombia	Colombia (Republic of)	introduced invasive	Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 439)
Costa Rica Costa Rica	Costa Rica (Republic of)		Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 345)
Indonesia Indonesia	Indonesia (Republic of)	introduced invasive	Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 439)
Japan Japan	Japan (country)	introduced invasive	Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 439)
North Korea North Korea	North Korea (Democratic People's Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
South Korea South Korea	South Korea (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Mexico Mexico	Mexico (United Mexican States)	introduced invasive	Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 439)
New Zealand New Zealand	New Zealand (country)	introduced invasive	Webb, C. J./Sykes, W. R./Garnock-Jones, P. J. (1988) (p. 344) "Waste land, grassland, coastal rocks, dunes and beaches, forest margins, crevices in walls and footpaths, gardens, pasture, roadsides, railway land".
Perú Perú	Perú (Republic of)	introduced invasive	Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 439)
Taiwan Taiwan	Taiwan Island	introduced invasive	Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 439)
Taiwan Taiwan	Taiwan Island	uncertain if introduced invasive	Ching-I Peng, ed. (2011) "Waste grounds and roadsides, low to mid elevations, common".
Vietnam Vietnam	Vietnam (Socialist Republic of)	introduced invasive	Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 439)

Indian Ocean
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Australia (Indian Ocean offshore islands) Christmas Island Group	Christmas Island	introduced invasive	Swarbrick, J. T. (1997) (p. 128)
Australia (Indian Ocean offshore islands) Cocos (Keeling) Islands	Cocos (Keeling) Islands	introduced	Williams, D. G. (1994) (p. 22)
Mauritius Mautitius Islands (Mauritius and Rodrigues)	Mauritius Island	introduced invasive	Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 439)

Control: 

Physical:  "Since plants do not regenerate from root fragments, physical control by cutting or mowing may control the plant".

Chemical:  "Effective pre-emergence herbicides are simazine or atrazine.  Seedlings and rosettes are sprayed with MCPA or 2,4-D"  (Weber, 2003; p. 413).

Additional information:
Additional online information about Sonchus oleraceus is available from the Hawaiian Ecosystems at Risk project (HEAR).

Information about Sonchus oleraceus as a weed (worldwide references) may be available from the Global Compendium of Weeds (GCW).

Taxonomic information about Sonchus oleraceus may be available from the Germplasm Resources Information Network (GRIN).

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