musk thistle: Carduus nutans (Asterales: Asteraceae)

musk thistle
Asterales > Asteraceae > 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

Biological Control of Invasive Plants in the Eastern United States - USDA Forest Service FHTET

Control of Problem Weeds in Range and Pasture - Montana, Utah, and Wyoming Cooperative Extension Services

Element Stewardship Abstract - The Nature Conservancy

Fire Effects Information System - USDA Forest Service, Rocky Mountain Research Station

Invasive Plant Manual - Southeast Exotic Pest Plant Council

Invasive Plants of Asian Origin Established in the United States and Their Natural Enemies - Volume 1 - USDA Forest Service

Nonnative Invasive Plants of Southern Forests - USDA Forest Service, Southern Research Station

Prescriptions for Specific Nonnative Invasive Plants - USDA Forest Service, Southern Research Station

Weeds Gone Wild Fact Sheets - Plant Conservation Alliance's Alien Plant Working Group

Weeds of the Week - USDA Forest Service, Northeastern Area, Forest Health Protection

Selected Images from Invasive.org

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Use 768x512 for Microsoft PowerPoint and use 1536x1024 for Prints and Publications.

Foliage; basal rosette Loke T. Kok, Virginia Polytechnic Institute and State University, Bugwood.org 768x512 / 1536x1024	Foliage; Richard Old, XID Services, Inc., Bugwood.org 768x512 / 1536x1024	Plant(s); lower stem Dan Tenaglia, Missouriplants.com, Bugwood.org 768x512
Plant(s); upper stem Dan Tenaglia, Missouriplants.com, Bugwood.org 768x512	Feature(s); Stem and foliage Mary Ellen (Mel) Harte, , Bugwood.org 768x512 / 1536x1024	Flower(s); USDA APHIS PPQ Archive, USDA APHIS PPQ, Bugwood.org 768x512 / 1536x1024
Plant(s); James H. Miller, USDA Forest Service, Bugwood.org 768x512 / 1536x1024	Flower(s); James R. Allison, Georgia Department of Natural Resources, Bugwood.org 768x512 / 1536x1024	Flower(s); Ricky Layson, Ricky Layson Photography, Bugwood.org 768x512 / 1536x1024
Flower(s); June James H. Miller, USDA Forest Service, Bugwood.org 768x512 / 1536x1024	Stem(s); June James H. Miller, USDA Forest Service, Bugwood.org 768x512 / 1536x1024	Flower(s); Ricky Layson, Ricky Layson Photography, Bugwood.org 768x512 / 1536x1024
Flower(s); Ready to set seed. Montana Wendy VanDyk Evans, , Bugwood.org 768x512 / 1536x1024	Flower(s); Steve Dewey, Utah State University, Bugwood.org 768x512 / 1536x1024	Flower(s); Richard Old, XID Services, Inc., Bugwood.org 768x512 / 1536x1024
Plant(s); Steve Dewey, Utah State University, Bugwood.org 768x512 / 1536x1024	Plant(s); Mary Ellen (Mel) Harte, , Bugwood.org 768x512 / 1536x1024	Plant(s); Steve Dewey, Utah State University, Bugwood.org 768x512 / 1536x1024
Flower(s); Steve Dewey, Utah State University, Bugwood.org 768x512 / 1536x1024	Plant(s); Vince Belleci, , Bugwood.org 768x512 / 1536x1024	Infestation; Norman E. Rees, USDA Agricultural Research Service, Bugwood.org 768x512 / 1536x1024
Infestation; Steve Dewey, Utah State University, Bugwood.org 768x512 / 1536x1024	Infestation; Vince Belleci, , Bugwood.org 768x512 / 1536x1024	Infestation; A pile of fill dirt left over winter. The following spring, the pile was covered in musk thistles. Kris Johnson, Great Smoky Mountains National Park, Bugwood.org 768x512 / 1536x1024
Diagram or Graphic; Britton, N.L., and A. Brown. 1913. Illustrated flora of the northern states and Canada. Vol. 3: 554. USDA PLANTS Database, USDA NRCS PLANTS Database, Bugwood.org 768x512 / 1536x1024

Invasive Reference(s):

Check Invasive.org for most current lists.

California - Noxious Weed Law
Colorado - Noxious Weed Law
Georgia - EPPC list
Illinois - Noxious Weed Law
Kansas - Noxious Weed Law
Maryland - Noxious Weed Law
Michigan - Noxious Weed Law
Minnesota - Noxious Weed Law
Missouri - Noxious Weed Law
Nebraska - Noxious Weed Law
New Mexico - Noxious Weed Law
Nevada - Noxious Weed Law
North Carolina - Noxious Weed Law
North Dakota - Noxious Weed Law
Ohio - Noxious Weed Law
Oklahoma - Noxious Weed Law
Oregon - Noxious Weed Law
Pennsylvania - Noxious Weed Law
South Carolina - EPPC List
South Dakota - Noxious Weed Law
Tennessee - EPPC List
Utah - Noxious Weed Law
Virginia - Invasive Alien Plant Species
Washington - Noxious Weed Law
West Virginia - Noxious Weed Law
Wyonming - Noxious Weed Law
Mid-Atlantic - EPPC List

Invasive Plants of the United States

musk thistle

Identification, Biology, Control and Management Resources

Selected Images from Invasive.org

Click on each thumbnail to download the image at 1536x1024 resolution or below for available resolutions.

Use 768x512 for Microsoft PowerPoint and use 1536x1024 for Prints and Publications.

Invasive Reference(s):

Check Invasive.org for most current lists.

External Links


				Bargeron, C.T., C.R. Minteer, C.W. Evans, D.J. Moorhead, G.K. Douce and R.C. Reardon. Technical Coordinators. 2008. Invasive Plants of the United States DVD-ROM: Identification, Biology and Control. USDA Forest Service. Forest Health Technology Enterprise Team. Morgantown, WV. FHTET-08-11.