(Juss.) Sweet, Asteraceae |
Present on Pacific Islands? yes
Primarily a threat at high elevations? no
Common name(s): [more details]
English: corn sow thistle, field milk thistle, field sow thistle, perennial sow thistle |
French: laiteron des champs |
Japanese: hachijona, taiwan-hachijona |
Spanish: cerraja, cerraja arvense, lechuguilla |
Habit: herb
Description:
Genus: "Annual or perennial erect herbs or subshrubs with hollow stems, milky latex, and alternate, sessile, simple to pinnately divided, often semiamplexicaul and auriculate leaves; flowering heads homogamous, ligulate, large or fairly large, many-flowered, pedunculate, disposed in cymose corymbiform or paniculiform capitulescences, the phyllaries membranous-margined, in several imbricated series, the receptacle naked; flowers ligulate, perfect, the anther bases sagittate, caudate-acuminate, the style branches thin, subobtuse; achenes obovate to narrowly oblong, ribbed, the pappus dimorphic, of fine narrow bristles and downy capillary hairs, weakly coherent at base." (Smith, 1991)
Species: "Coarse, freely branched herb 0.3-2 m high, perennial, with abundant milky latex...; flowers dull red in center, yellow at margin, the styles yellow" (Smith, 1991; p. 265).
"A deep-rooted perennial with milky sap in all plant parts; roots creamy-white, fleshy, vertical and horizontal, widely spreading, to 6 mm in diameter; often crooked and easily broken, with buds at close intervals; stems erect 0.5 to 1.5 m tall, hollow, smooth on lower part of plant but often glandular-hairy above, often branched above; leaves variable in size and shape; rosette leaves up to 30 cm long, petiolate, cut into backward-curving lobes, terminal lobe tips broadly triangular; stem leaves crowded on lower stem with weak prickles on margins; upper stem leaves sparse alternate, small, divided or almost entire, margins weakly prickled, sessile and clasping the stem; inflorescence composed of flower heads of 2 to 5 cm in diameter; in large open corymbose clusters; flower florets bright yellow, perfect, ligulate; involucre about 1.5 cm long, the bracts linear-lanceolate, obtuse, the outer densely covered with coarse gland-bristles; peduncle glandular pubescent or smooth; fruit a dark brown to reddish-brown achene, 2.5 to 4.5 mm long, narrowly ovate with the base somewhat truncate, the apex with an expanded collar, somewhat flattened with longitudinally 5 prominent ribs on each side, often slightly curved, transversely wrinkled; pappus composed of numerous simple, persistent, white hairs to 1.5 cm long. This plant can be distinguished from other Sonchus species by its long, creeping thickened roots with many buds; its relatively large inflorescence of yellow, ligulate flowers; the 5-ribbed achenes; and the presence of glandular hairs on the peduncles of most biotypes. The hollow stem and milky juice in all plant parts separate it from thistles in other genera" (Holm et al., 1997; p. 789).
Habitat/ecology: In Fiji, "found as a naturalized weed in open places, along roadsides, and sometimes in openings along streams in dense forest from near sea level to 400 m" (Smith, 1991; p. 265).
Habitat/ecology: In Fiji, "found as a naturalized weed in open places, along roadsides, and sometimes in openings along streams in dense forest from near sea level to 400 m" (Smith, 1991; p. 265).
Propagation: Seed
Native range: Eurasia, now naturalized elsewhere (Smith, 1991; p. 265).
Presence:
Pacific | |||
Country/Terr./St. & Island group |
Location |
Cited status &
Cited as invasive & Cited as cultivated & Cited as aboriginal introduction? |
Reference &
Comments |
Fiji
Fiji Islands |
Viti Levu Island |
introduced
invasive |
Smith, Albert C. (1991) (p. 265)
Vouchers cited: Smith 8684, DA 2534, DA 9379, DA 9647, DA 11109 |
New Caledonia
Îles Bélep (Belep Islands) |
Île Art |
introduced
|
MacKee, H. S. (1994) (p. 38)
Voucher cited: MacKee 30545 |
New Caledonia
Îles Loyauté (Loyalte Islands) |
Îles Ouvéa (Ouvea Atoll) |
introduced
|
MacKee, H. S. (1994) (p. 38)
Voucher cited: MacKee 18905 |
New Caledonia
New Caledonia Archipelago |
Île Grande Terre |
introduced
invasive |
Tassin, Jacques (2005) |
New Caledonia
New Caledonia Archipelago |
Île Grande Terre |
introduced
|
MacKee, H. S. (1994) (p. 38)
Vouchers cited: MacKee 13473, MacKee 40954, MacKee 45154 |
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
|
MacKee, H. S. (1994) (p. 38)
Vouchers cited: MacKee 15790, MacKee 33826 |
Philippines
Philippine Islands |
Philippine Islands |
introduced
invasive |
Merrill, Elmer D. (1923) (p. 621)
In waste places, along trails, old gardens, talus slopes, etc., altitude 1,200 to 2,000 m; unquestionably introduced. |
Samoa
Western Samoa Islands |
Western Samoa Islands | Swarbrick, John T. (1997) (p. 97) | |
Tonga
Tonga Islands |
Tonga Islands | Swarbrick, John T. (1997) (p. 97) |
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 |
introduced
invasive |
Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 787) |
Central America
Central America (Pacific rim) |
Guatemala (Republic of) |
introduced
invasive |
Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 793) |
China
China |
China (People's Republic of) | Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 344) | |
China
China |
Hong Kong |
native
|
Wu, Te-lin (2001) (p. 287)
In wasteland. |
Indonesia
Indonesia |
Indonesia (Republic of) | Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 787) | |
Japan
Japan |
Japan | Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 787) | |
Japan
Japan |
Japan |
introduced
|
Mito, Toshikazu/Uesugi, Tetsuro (2004) (p. 190) |
South Korea
South Korea |
South Korea (Republic of) | Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 787) | |
Mexico
Mexico |
Mexico (United Mexican States) |
introduced
invasive |
Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 787) |
New Zealand
New Zealand |
New Zealand (country) |
introduced
invasive |
Webb, C. J./Sykes, W. R./Garnock-Jones, P. J. (1988) (p. 343)
"Roadsides, hedges, swamps, cultivated land". |
Taiwan
Taiwan Island |
Taiwan Island |
probably native
|
Ching-I Peng, ed. (2013)
"Wastelands and river banks, low to mid elevations, common". |
Thailand
Thailand |
Thailand (Kingdom of) | Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 787) |
Control:
Biological: "The leaf-gall fly (Cystiphora sonchi) of Europe and the former Soviet Union offer hope of supressing S. asper and S. arvensis in Canada. Females lay eggs on the undersides of leaves, forming up to 270 galls/plant and this insect was initially released in Canada in 1981" (Peschken, 1982, cited in Holm et al., 1997; p. 800).