Bull thistle, a member of the Asteraceae family, is yet another herbaceous biennial on our list of invasives. Unfortunately, bull thistle can flourish in an array of sites ranging from meadows, ...

Native to Europe but common in the U.S. today as well, milk thistle is a flowering plant in the daisy (Asteraceae) family of flowers. This is the same plant family that has more than 30,000 other ...

Sow thistle is commonly found in crops, gardens and waste areas. As with many members of the Asteraceae family, it starts life as a rosette, and then bolts to form an upright flower stem. Sow thistle ...

Canada thistle is a colony-forming perennial from deep and extensive horizontal roots. Stems are 1 to 4 feet tall, ridged, branching above. Leaves are alternate, lacking petioles, oblong or ...

Winged thistle is a winter annual, which means it generally establishes from seed in autumn, grows as a typical thistle rosette over winter, then develops an upright flower stem in spring, from which ...

Canada thistle, a terrestrial herbaceous perennial in the Asteraceae family, is an open-land invasive that prefers disturbed upland areas as well as wet areas with water fluctuations. Canada thistle ...