PERENNIAL SOWTHISTLE - Asteraceae - (Sunflower family)

The spring leaves arise from robust lateral roots, some leaves are full but some being rag like on the edge as a dandelion.  The central vein and the edges of the leaves have red prickles. The clasping alternate leaves grow smaller and fewer upward on the stem.  Several stiff stems grow 2 to 4 feet tall, not much branched producing a tall thin plant that exudes a milky sap if broken.  One to several buds in the shape of a vase form at the tops of the stems.

The upper portion of the stem, including the vase shaped bud, is covered with tiny glandular hairs which exude a sticky substance.  The flowers are bright yellow, as a dandelion, and about the same size or somewhat larger.  The abundant seeds are also much alike and are distributed by the wind in the same manner.

The roots creep outward underground and are creamy to reddish in color, producing new plants at joints as they grow.
The presence of Perennial Sowthistle indicates a wet saline soil, it does well in pasture land.

The following is courtesy of Weeds of the West:
A perennial, spreading from horizontal rhizome-like roots. Plants are usually 2 to 4 feet tall, succulent, and exude a milky juice when injured. Leaves have a clasping base and mildly prickly margins which vary from deeply toothed to nearly entire. Upper leaves are fewer and much smaller than the basal ones. The flower head is 1 to 2 inches wide, and rich yellow in color.

Numerous gland-tipped hairs on involucre bracts and flower stalks help distinguish this species. Seeds are dark brown, prominently ridged and wrinkled, with a tuft of soft white pappus bristles.

Perennial sowthistle is a native of Europe or Eurasia. It is widely distributed in North America, and considered noxious in many states and provinces. It is common in gardens, cultivated crops, ditchbanks, and fertile waste areas where adequate water is available. Marsh sowthistle (listed by various authors as S. uliginosus Bieb., S. arvensis L. ssp. uliginosus (Bieb.) Nyman, or S. glabrescens Jord.) is a similar perennial; the most important difference being a lack of gland-tipped hairs.

(Courtesy of Weeds of the West)

Growth Habit: Perennial, up to 4` tall.

 

Leaves: Prickly serrations on margins, may be deep lobed, narrow at base. Upper leaves clasp stem. Alternate, usually crowded on lower ½ of stem.

 

Stems: Erect, finely grooved, hollow between joints, milky juice.

 

Flower: Bright yellow, flat topped, clustered, 1 to 2" in diameter

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Roots: Creeping horizontal roots, give rise to new shoots at joints. Yellowish white with milky juice.

 

Seeds: Reddish brown, 1/8" long, 5 to 7 lengthwise ribs.

 

Other: Reproduces by seed and creeping roots.

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