This annual is a true member of the lettuce family and is quite often referred to as "compass" plant. It derives this unusual name from its sensitivity to sunlight which causes leaves to be turned on edge and point toward north and south. Although prickly lettuce is a member of the lettuce family, it has no particular value. Leaves are long, spear-shaped, deeply lobed and the edges are lined with sharp spines. The surface of the leaf is smooth, but the spines also cover the lower surface of the mid-vein. when allowed to mature, small, yellow ray flowers are found in terminal clusters.