Bull thistle (Cirsium vulgare)
Image courtesy Ken French
Bull thistle (Cirsium vulgare)
Image courtesy Eric Coombs
Bull thistle (Cirsium vulgare)
Image courtesy Ken French
EDRR Species?: 
No

Other common names
Common thistle, Spear thistle

Description
Biennial, blooms July to September and grows two to five feet tall. It has many branches sporting green to brown spines and hairs. Leaves are pinnately lobed, hairy, prickly on the upper side and cottony underneath. Flowers are 1 1/2 to 2 inches wide and clustered at ends of branches. Flowers are dark purple. Seeds are topped by a circle of plume-like white hairs.

Impacts
A wasteland weed that, if not controlled, presses into farmland. It is most commonly found in pastures, rangeland and newly logged sites. It takes the place of forbs and grasses.