Thistles often get a bad rap, since some members of this large and diverse plant genus are considered noxious weeds.
According to the U.S. Forest Service, thistle species can be difficult to distinguish, but it's worth doing so because the 'good thistle' (Wavyleaf Thistle Cirsium unulatum) is frequently visited by bumblebees and other pollinating insects. And their pappus bristles are used by birds, such as goldfinches, to line their nests.
A comprehensive writeup is on the Forest Service's "Plant of the Week" page with pictures and detailed information on how to tell the good thistles from the bad. Read the writeup here.
Photo: leaves of Wavyleaf Thistle
Photo credit: U.S. Forest Service
A comprehensive writeup is on the Forest Service's "Plant of the Week" page with pictures and detailed information on how to tell the good thistles from the bad. Read the writeup here.
Photo: leaves of Wavyleaf Thistle
Photo credit: U.S. Forest Service