abstract:Sonchus arvensis (Corn Sow Thistle, Dindle, Field Sow Thistle, Gutweed, Swine Thistle, Tree Sow Thistle, Field Sowthistle,Sonchus arvensis at USDA PLANTS Database Field Milk Thistle Sonchus arvensis at Plants For A Future) is a medicinal plant. It is an invasive species in the Great Lakes region and was first sighted in 1865.