Click on images to enlarge
infestation (Photo: Sheldon Navie)
habit (Photo: Sheldon Navie)
habit (Photo: Sheldon Navie)
basal rosette of leaves (Photo: Sheldon Navie)
the relatively large, deeply-lobed, lower leaves (Photo: Sheldon Navie)
smaller, stem-clasping, upper leaves (Photo: Sheldon Navie)
old flower-heads and mature fruit with fluffy seeds (Photo: Sheldon Navie)
close-up of fluffy seeds (Photo: Sheldon Navie)
close-up of seeds, with their hairs removed (Photo: Steve Hurst at USDA PLANTS Database)
young seedling (Photo: Sheldon Navie)
young plant (Photo: Sheldon Navie)
close-up of yellow flower-head with numerous small 'petals' (Photo: Sheldon Navie)
Scientific Name
Sonchus oleraceus L.
Synonyms
Sonchus tenerrimus L. (misapplied)
Family
Asteraceae (Queensland, New South Wales, the ACT, Victoria, Tasmania, Western Australia and the Northern Territory)Compositae (South Australia)
Common Names
annual milk thistle, annual sow thistle, annual sowthistle, colewort, common sow thistle, common sow-thistle, common sowthistle, field sow-thistle, hare's lettuce, hare's-lettuce, milk-thistle, milk thistle, small sow thistle, smooth sow-thistle, smooth sowthistle, sow thistle, sow-thistle, sowthistle
Origin
Native to northern Africa (i.e. Algeria, Egypt, Libya, Morocco and Tunisia), Europe, western and northern Asia (i.e. Afghanistan, Iran, Iraq, Jordan, Lebanon, Syria, Turkey, Armenia, Azerbaijan, Georgia, Russia, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, northern and central China and Korea) and the Indian Sub-continent (i.e. northern India, Nepal and northern Pakistan).
Naturalised Distribution
This species is very widely naturalised throughout Australia, though it is less common in the driest and northernmost parts of the country. It is found throughout Queensland, New South Wales, the ACT, Victoria, Tasmania, South Australia and Western Australia and is also naturalised in the southern and central parts of the Northern Territory). Also naturalised on Lord Howe Island, Norfolk Island and Christmas Island.
Naturalised overseas in tropical and southern Africa, New Zealand, North America (i.e. the USA, Canada and Mexico), Central America, the Caribbean, South America, Mauritius, south-eastern Asia (i.e. Vietnam, the Philippines, Taiwan and Papua New Guinea) and on several Pacific islands (i.e. the Galápagos Islands, Fiji, French Polynesia, Guam, Hawaii, Kiribati, the Marshall Islands, New Caledonia, Niue and Tonga).
Notes
Common sowthistle (Sonchus oleraceus) is regarded as an environmental weed in Victoria, Western Australia, South Australia, New South Wales, Queensland, Tasmania and the Northern Territory.