What is "lactuca canadensis"

Lettuce \Let"tuce\ (l[e^]t"t[i^]s), n. [OE. letuce, prob. through Old French from some Late Latin derivative of L. lactuca lettuce, which, according to Varro, is fr. lac, lactis, milk, on account of the milky white juice which flows from it when it is cut: cf. F. laitue. Cf. Lacteal, Lactucic.]

1. (Bot.) A composite plant of the genus Lactuca ( Lactuca sativa), the leaves of which are used as salad. Plants of this genus yield a milky juice, from which lactucarium is obtained. The commonest wild lettuce of the United States is Lactuca Canadensis.

2. United States currency; dollar bills; greenbacks. [slang]

   Hare's lettuce, Lamb's lettuce. See under Hare, and Lamb.

   Lettuce opium. See Lactucarium.

   Sea lettuce, certain papery green seaweeds of the genus Ulva.

Lactuca canadensis is a species of wild lettuce known by the common names Canada lettuce, Canada wild lettuce, tall lettuce, and Florida blue 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.

Lactuca canadensis is a generally biennial herb in the daisy family growing from a taproot to maximum heights of 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 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.