Western Rattlesnakeroot (Nabalus hastatus (Less.) A.Heller)

Also known as western rattlesnake root, western white lettuce; also classified as Prenanthes alata (Hook.) D. Dietr., Nabalus alatus Hook., Sonchus hastatus Less.

For some time this species was classified by many authorities in the Prenanthes genus, as Prenanthes alata. It was more recently moved into the Nabalus genus, which would normally make its name Nabalus alatus, as that name (1833) is older than Nabalus hastatus, and some authorities call it by that name. However, the oldest name for this species is Sonchus hastatus Less. (1831), so retaining the epithet from that name leads to Nabalus hastatus, the name that POWO uses. We follow their scheme but note that some of these other names are also still in use, even on various contemporary websites.