Sonchus asper

Sonchus asper is an annual or biennial herb sometimes reaching a height of 200 centimetres (6.6 ft) 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 leaves and stems emit a milky sap when cut. One plant will produce several flat-topped arrays of flower heads, each head containing numerous yellow ray flowers but no disc flowers.[5][6]

Sonchus asper is native to Europe, North Africa, and western Asia. It has also become naturalized on other continents and is regarded as a noxious, invasive weed in many places. Its edible leaves make a palatable and nutritious leaf vegetable.[7][8][9][10][11]

It is found in cultivated soil, pastures, roadsides, edges of yards, vacant lots, construction sites, waste areas and in grasslands.[12]

• Spiny Sowthistle in Virginia Tech Weed Identification Guide
• WeedAlert.com's article on the Spiny Sowthistle
• photo of herbarium specimen at Missouri Botanical Garden, collected in Madagascar in 1932

• Media related to Sonchus asper at Wikimedia Commons