- A perennial that spreads by roots and seeds
- Grows 1 to 4 feet tall
- Has clusters of small, white to purple flowers at the end of the stems
- Leaves are very spiny – it hurts to touch this weed!
- Grows in moist and disturbed sites
- This invasive weed is very aggressive and difficult to control
- Pulling and burning do not control this weed, as they favor root resprouting
- Chemical controls are needed