Musk thistle was introduced into the eastern North America in the early 19th century, and has been an invasive species there since.

This thistle may resemble musk thistle (Carduus nutans) in appearance.

KSU: "Biological Control of the Musk Thistle in Kansas"

Carduus nutans (Musk Thistle or Nodding Thistle)

Dr. Louda has studied the thistle flowerhead weevil that was imported from France and Italy in the 1970's to control a weed called the musk thistle, which spread across grazing land.

U.S. National Invasive Species Information Center: Species Profile - Musk Thistle (Carduus nutans) - Lists general information and resources.

Other species, including Dwarf Thistle Cirsium acaule, Musk Thistle Carduus nutans, and Melancholy Thistle Cirsium heterophyllum have also been suggested.

The non-native flower head weevil Rhinocyllus conicus has the potential to damage the thistle; it was purposely introduced to North America in an attempt to control various species of invasive thistles which are noxious weeds, including musk thistle.

The path to the pool covered over in a day with new grass and nodding thistles.

The flower heads commonly droop to a 90 to 120 angle from the stem when mature, hence its alternate name of "Nodding thistle".

Nodding thistle (Carduus nutans)

Carduus nutans (Musk Thistle or Nodding Thistle)

USDA Plants Profile - Carduus nutans (nodding plumeless thistle)

Carduus nutans, with the common names Musk thistle, Nodding thistle, and Nodding plumeless thistle, is a biennial herb in the Asteraceae-sunflower family.

This thistle may resemble musk thistle (Carduus nutans) in appearance.

Nodding thistle (Carduus nutans)

U.S. National Invasive Species Information Center: Species Profile - Musk Thistle (Carduus nutans) - Lists general information and resources.

Other species, including Dwarf Thistle Cirsium acaule, Musk Thistle Carduus nutans, and Melancholy Thistle Cirsium heterophyllum have also been suggested.