Lactuca biennis is a species of wild lettuce known by the common names tall blue lettuce and blue wood lettuce. It is native to the eastern half of the United States and Canada, but it can also be found in much of the western half as an introduced species. This is a biennial herb in the daisy family growing from a taproot to heights anywhere from one half to four meters. There are deeply lobed, toothed leaves all along the stem. The top of the stem bears a multibranched inflorescence with many flower heads. Each head is just over a centimeter wide and has many whitish to light blue ray florets. The fruit is a mottled achene about half a centimeter long with a brownish pappus.

External links

• Jepson Manual Treatment
• USDA Plants Profile
• Photo gallery