Corn Sow-thistle, Corn Sow Thistle, Field Sowthistle,Field Sow-thistle, Field Sow Thistle, Perennial Sow-thistle, Perennial Sow Thistle: Sonchus arvensis ssp. arvensis (Synonym: Sonchus arvensis var. arvensis) -
Field Sow-thistle, Marsh Sow-thistle, Wet Ground Sow-thistle: Sonchus arvensis ssp. uliginosus (Synonyms: Sonchus arvensis var. glabrescens, Sonchus uliginosus) -
Prickly Sow Thistle, Prickly Sow-thistle, Spiny Sowthistle, Spiny-leaf Sow-thistle, Spiny Sow-thistle: Sonchus asper (Synonyms: Sonchus asper ssp. asper, Sonchus asper ssp. glaucescens, Sonchus nymanii, Sonchus oleraceus var. asper) -
Annual Sow Thistle, Common Sowthistle, Common Sow-thistle, Common Sow Thistle: Sonchus oleraceus -