About Lactuca biennis (Moench) Fernald
Lactuca biennis (Moench) Fernald is a North American species of wild lettuce, commonly called tall blue lettuce and blue wood lettuce. It is widespread across most of the United States and Canada, ranging from Alaska and Yukon in the north south to California, New Mexico, and Georgia. This plant is a biennial herb that belongs to the dandelion tribe of the daisy family. It grows from a taproot and reaches heights between 0.5 and 4 meters (20 inches to over 13 feet). Deeply lobed, toothed leaves grow all along its stem. The top of the stem produces a multibranched inflorescence that holds many flower heads. Each flower head is just over 1 centimeter (0.4 inches) wide, and contains many whitish to light blue ray florets, with no disc florets. Its fruit is a mottled achene about 0.5 centimeters (0.2 inches) long, with a brownish pappus. Lactuca biennis was first formally described botanically in 1794 under the name Sonchus biennis, and was later transferred to the Lactuca genus in 1940.
