Smooth sowthistle (common sowthistle, milk thistle, annual sow-thistle)
Annual, lactiferous, seed-propagated weed with strong, cone-shaped taproot. S. oleraceus produces latex and is a preferred feed for birds, chicken and geese.
Flower heads light yellow to greenish yellow (Sonchus arvensis: intensive yellow). Leaves and stems contain milky sap. Soft, floppy, shiny, greasy, bluegreen leaves.
Young Plant: Round, often flatly sinuate in front, light green, entire, petiolate.
Stems: Erect, thick, ramified, up to 80 cm-100 cm (2.62 - 3.28 ft) high.
Leaves: First leaves nearly circular, with fine teeth; following leaves runcinate-pinnatifid or undivided, soft, blue-green, enclosing the stalk sagittately, prickly dentate.