Smooth Sow Thistle?

seemed similar-ish to ragwort but the leaves seem more angular. You can make out the 'false' spines on the young leaf in the 6th photo. Leaf miners and aphids seemed to like this plant. There are a number of similar species such as prickly sow thistle, corn sow thistle and Beaked Hawks Beard. Sow thistles are edible even though they have white sap which is apparently a general rule with wild plants indicating the plant can't be eaten: http://www.eattheweeds.com/sonchus-sow-thistle-in-a-pigs-eye-2/. About S. oleraceus: 'Leaves are eaten as salad greens or cooked like spinach. This is one of the species used in Chinese cuisine as kŭcài (菜; lit. bitter vegetable). Blanching or boiling removes bitter flavour' (taken from wikipedia http://en.wikipedia.org/wiki/Sonchus_oleraceus#Nutritive_qualities ).