This native, erect perennial grows from 1-3 feet tall. The smooth stems and alternate leaves contain a white, milky juice. Unstalked basal leaves, up to 5 inches long and 1 inch wide, are usually deeply divided into a few widely spaced pointed lobes. The upper leaves are smaller, less divided or often smooth edged. From 20-50 flower heads occur in an open, branching cluster (panicle) at the top of the plant (A). Each is 1 inch wide and contains from 19-21 light blue, strap-shaped ray florets with white anthers and two conspicuous, deep blue, coiled or curving style branches (B,C). Clusters of seeds, each bearing a tuft of hairs, produce a conspicuous, fuzzy, white seed head (D). Fresh flowers and mature seed heads are often present at the same time. Blue Lettuce is shorter (1-3 feet tall), has smaller, less deeply divided or undivided upper leaves, and blue flowers twice as large as Florida Lettuce (Lactuca floridana), a similar but more robust (6-8 feet tall) local species. Wild Lettuce (Lactuca canadensis) and Prickly Lettuce (Lactuca serriola) have yellow flowers.