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Perennial Sowthistle (Sonchus arvensis)

Perennial sowthistle is a member of the Aster or Sunflower family, Chicory tribe. It is an introduced, creeping perennial which reproduces by seeds and horizontal roots. All plant parts are filled with a bitter, milky juice. The plant is 2 to 4 feet tall. The stem is erect, stout, smooth, and is unbranched except at the top. The leaves are alternate and light green. The lower leaves are 6 inches to 1 foot long, with deeply cut, backwardspointed side lobes. The upper leaves are slightly toothed. The flower is bright yellow and is 1 to 2 inches wide. Seeds are brown, ridged, and wrinkled with a tuft of fine white hairs.

Perennial sowthistle is common in cultivated areas, ditch banks, meadows, and neglected areas. This plant is scattered throughout Colorado and is considered noxious in many of our neighboring states

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