Prickly Sow-thistle

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.

This plant is native to Europe, but is also a common weed in North American roadsides, landscapes, and pastures. Its edible leaves make a palatable and nutritious leaf vegetable.

The plant can be classified as a noxious weed. Care should be exercised when weeding or handling the plant. Many people report irritations ranging from burning sensations, redness, and mild to severe rashes when coming in contact with the spines. Hands should be rinsed immediately after handling the plant, as the chemical irritant can spread easily via contact to other parts of the body, in a similar way to poison ivy.