Florida lettuce, or woodland lettuce, is an annual or biennial with open, branched clusters of bluish flowers. Flowerheads with up to 17 florets per head. There are no disk flowers. Ray flowers light blue to nearly white, opening a few at a time. Blooms August-October. Leaves mostly on stems, to 12 inches long, deeply lobed almost to midrib, toothed. All parts of plant contain a white, milky juice.
Similar species: There are 7 species of Lactuca in our state. Prickly lettuce (L. serriola) has light yellow flowers that turn blue on wilting; its clasping leaves either lack lobes or are deeply lobed and cut, always with prickly teeth on the margins and midrib on the underside of the leaf. Wild lettuce (L. canadensis) has orangish flowers; its leaves do not clasp the stems and are either entire (unlobed) without prickles or deeply lobed with prickles.