Sonchus - Sow-thistle family
Sonchus arvensis Perennial Sow-Thistle
Need text here.
Sonchus asper - Rough or Prickly Sow-thistle
The auricles of the leaves are pointed back past the stem. The leaves are more prickly than S. oleraceus and the flowers tend to be a darker yellow and the flowers fade quicker in the winter.
Sonchus oleraceus - Smooth Sow-thistle
The auricles of the leaves are rounded, like a wheel against the stem.