Carduus nutans L.
Synonym(s): nodding plumeless thistle, nodding thistle, bristle thistle

Musk thistle is an herbaceous, biennial plant that grows to 6 ft. (1.8 m) tall. It has become a serious invader of open lands throughout the continental United States. It can be recognized by its showy, red-purple flowers and very spiny stem and leaves. Flowering occurs from June to September. The large, disk-shaped, terminal flower heads droop when mature. Musk thistle invades a variety of disturbed areas. Pastures are particularly at risk because musk thistle is unpalatable to livestock. Once established it can spread rapidly due to high seed production (as much as 120,000 seed per plant). Musk thistle is native to Western Europe and was accidentally introduced into the United States in the early 1900s.

Identification, Biology, Control and Management Resources