Prickly Lettuce (Lactuca serriola) vs. American Wild Lettuce (Lactuca canadensis)
Updated October 17th, 2025These two lettuces, one native and one introduced and invasive, are sometimes confused. Although they are usually easy to distinguish, it can be hard to learn how to do so because of high variability within each species. Close examination of the seeds, or presence/absence of prickles are most reliable for ID, whereas the other traits are largely-overlapping. L. serriola ranges farther west and favors drier, sunnier, more barren habitats, in the east strongly favoring anthropogenic habitats, whereas L. canadensis ranges farther north and south in the east, tolerates more shade, and prefers moister, richer soil and more competing vegetation.
