Weeds

Lettuce, Prickly

Lettuce, Prickly
Tap to view larger image
 
Prickly lettuce is a annual weed growing from 1 to 5' in height. Prickly lettuce has a deep tap root which will exude a milky sap. The leaves are alternate, clasp the stem, and are deeply lobed with spiny margins. The leaves have a row of spines along the mid-vein of the lower surface which is a distinguishing characteristic of this plant. The flowers of prickly lettuce are yellow in color and approximately one third of an inch in diameter. Flowers are produced in late spring to early summer. Individual plants can produce from 35 to 2,300 flowers. Each flower head contains an average of 20seeds, giving an estimated seed production of 700 and 46,000 seeds per plant, respectively. Most seeds are viable and ready to germinate immediately after dispersal. Prickly lettuce forms only a short-term seed bank, with seeds surviving 1–3 yr in soil.