About Lactuca ludoviciana (Nutt.) Riddell
Lactuca ludoviciana, commonly called biannual lettuce, is a North American species of wild lettuce. It is widespread across much of central and western Canada, as well as central and western United States, ranging from Ontario west to British Columbia and south to Louisiana, Texas, and California. Most of its confirmed populations occur on the Great Plains; populations located west of this region are very likely naturalized introductions. Lactuca ludoviciana is a biennial herb belonging to the dandelion tribe of the daisy family. It grows from a taproot and reaches a maximum height of 150 cm (5 feet). The top of its stem produces a multibranched inflorescence that holds many flower heads. Each flower head contains 20 to 50 yellow ray florets, and does not produce any disc florets. This species has been observed to hybridize extensively with Lactuca canadensis, making the two species difficult to distinguish from one another.
