Prickly lettuce is a common introduced plant. It has been documented in every one of the lower 48 states as well as Hawaii (USDA, 2014). It is common to open soils and is seen on the perimeters of many crop fields.
It is an annual or winter annual and a member of the sunflower family. It produces many dandelion-like flowers. The stem tends to have a reddish appearance and the entire plant is filled with a white sap when broken. The leaves have a prominent midrib, fine spines with prickly edges, and are deeply lobed. The leaves get progressively smaller as they near the top of the plant.
Prickly lettuce is considered edible.
USDA, NRCS. 2014. The PLANTS Database (http://plants.usda.gov, 18 March 2014). National Plant Data Team, Greensboro, NC 27401-4901 USA.