Prickly Slow-thistle (Sonchus asper)

Sonchus asper (sharp-fringed sow thistle, prickly sow thistle, spiny sow thistle, or spiny-leaved sow thistle) is an annual plant with spiny leaves and yellow flowers resembling those of the dandelion. The leaves are bluish-green, simple, lanceolate, with wavy and sometimes lobed margins, covered in spines on both the margins and beneath. The base of the leaf surrounds the stem. The plant can reach 180 cm (6 ft) in height. The leaves and stems emit a milky sap when cut. The flowers grow in clusters and the end of the stems. Wikipedia 
Daisy Family,

25/7/14
Park/Patch of land

Flower

Leaf

Flower