"A plant of the genus <i>Sonchus</i>, primarily <i>S. oleraceus</i>, a weed of waste places, probably native in Europe and central Asia, but now diffused nearly all over the world. It is a smooth herb with a milky juice, bearing runcinate-pinnatifid leaves and rather small yellow flower heads... 1. upper part of the stem with the heads; 2. one of the basal leaves; a, a flower; b, the achene with the pappus." &mdash;Whitney, 1889

Sow Thistle - Stem with Heads, Basal Leaves, Flower, Achene with Pappus

"A plant of the genus Sonchus, primarily S. oleraceus, a weed of waste places, probably native in Europe…