Sonchus arvensis, the field milk thistle,Sonchus arvensis at Plants For A Future field sowthistle, perennial sow-thistle, corn sow thistle, dindle, gutweed, swine thistle, or tree sow thistle, is a species of flowering plant in the family Asteraceae. S. arvensis often occurs in annual crop fields and may cause substantial yield losses.
Description The plant grows up to in height, with leaves long and wide. It produces conspicuous yellow flowerheads about wide, which are visited by various types of insects—especially hoverflies of the genus Eristalis.
Distribution Sonchus arvensis is native to Eurasia, where it is widespread across most of the continent.Altervista Flora Italiana, Sonchus arvensis L. includes photos, European distribution map It has also become naturalized in many other regions, and is considered an invasive noxious weed in some places, such as North America (including Prince Edward Island), Russia, New Zealand, and Australia.Davidse, G., M. Sousa-Peña, S. Knapp & F. Chiang Cabrera. 2015. Asteraceae. 5(2): ined. In G. Davidse, M. Sousa Sánchez, S. Knapp & F. Chiang Cabrera (eds.) Flora Mesoamericana. Universidad Nacional Autónoma de México, México, D.F.Atlas of Living Australia
It grows in areas such as pastures, roadsides, bushlands and the shorelines of lakes, riversCorn sowthistle (Sonchus arvensis) by NSW WeedWise and sea coast.
A study conducted in 2003 has shown that with future global atmospheric carbon levels, S. arvensis shows increased growth with increased atmospheric carbon which could potentially expand its range and outcompete native species.
Uses The young leaves, when less than a few inches long and not bitter in taste, can be mixed with other greens to make salad. They can also be boiled in a small quantity of water, changed once. The plant can contain toxic nitrates.
References
External links Tropicos.org: photo of herbarium specimen at Missouri Botanical Garden