Sonchus

Sonchus 

(sow thistle), a genus of plants of the family Com-positae. They are annual, biennial, or perennial herbs; some are subshrubs. The plants usually have a milky juice. The leaves are entire or pinnatipartite. The yellow, ligulate flowers are in heads, gathered into a common inflorescence. The fruit is an achene with a white pappus.

There are approximately 70 species of Sonchus, distributed in Eurasia and Africa. A few species are cosmopolitan weeds. Of the six species found in the USSR, three are weeds. The most pernicious weed is the field sow thistle (5. arvensis), a sucker-forming perennial that infests mainly spring grain and wide-row crops. It grows in kitchen gardens, in wastelands, near roads, and along rivers. The plant propagates vigorously by means of root cuttings that are formed when the soil is tilled. The common sow thistle (S. oleraceus) and the prickly sow thistle (S. asper) are found in gardens, orchards, refuse sites, and, less frequently, seeded fields. Sow thistles are good fodders, especially for swine.

The Russian common name for the genus, osot, is sometimes used to designate the genus Cirsium, particularly the creeping thistle (C. arvense).