Lactuca canadensis

Lactuca canadensis is a species of wild lettuce known by the common names Canada lettuce, Canada wild lettuce, and tall lettuce. Its true native range is not clear, but it is considered to be a native of the eastern and central parts of North America. It naturalized in the western part of the continent as well as in Eurasia. Generally, Lactuca canadensis is a biennial herb in the daisy family growing from a taproot to maximum heights of 50–200 cm (19.5–78.5 in) or more. The leaves are deeply lobed and occasionally toothed. The top of the stem bears an inflorescence with many flower heads, each up to 1 cm (0.5 in) wide when open. The heads have many pale yellow ray florets, but no disc florets. The fruit is a dark-colored achene about half a centimeter (0.2 inches) long with a white pappus....read more on Wikipedia.