Perennial (or Corn) Sow-thistle is a common weed, especially of cultivated ground and field edges.
It has golden yellow flowers in heads up to 5cm across, and the bracts and upper part of the stem are covered in sticky-tipped hairs. These hairs are the main distinguishing feature from the Smooth and Prickly Sowthistles, which also have smaller paler yellow flowers (up to 2.5cm across).

Flower head-on		Leaves (edged with spines)