Summary ⁶

Musk Thistle (Carduus nutans), also known as Nodding Thistle or Nodding Plumeless Thistle is a biennial forb native to Europe and Asia. During the first year of growth, a rosette forms in spring or fall. During the second year in mid to late spring, the stem bolts, flowers, sets seed, and the plant dies. Musk thistle reproduces solely from seed, so the key for successful management is to prevent seed production. The terminal flower heads are purple, 1.5 to 3 inches in diameter, and bend over as if nodding. Flowering occurs from May to September. A robust plant may produce 100 or more flowering heads and up to 20,000 seeds per plant.

Source:
https://drive.google.com/file/d/1BxKYg66YNE3mfhGla0uB2k4ugVtH0ePd/view
http://www.cwma.org/Muskthistle.html

Identification ⁷

Height: Up to 6 feet tall
Shape: Upright forb
Flowers: Flower heads are terminal, solitary, 1.5-3 in wide, and usually nodding. Flowers are deep rose, violet or purple, occasionally white. Flowers have broad lance-shaped, spine-tipped bracts below. Flowers May-July.
Stems: Solitary stem or several stems from one base, and highly branched above
Leaves: Leaves are alternate, waxy, spiny margined, deeply lobed, and dark green with a prominent light green to white midrib. The leaves extend onto the stem and sometimes down below the point of attachment. Basal rosettes are well developed, leaves elliptical to lanceolate, 6-14 in, smooth to densely hairy.
Fruit: One-seeded oblong fruit (achene) about 0.2 inches long, shiny, yellowish-brown with a plume (pappus) of white hair-like bristles.
Toxic: No
Root: Fleshy taproot

Source:
https://drive.google.com/file/d/1BxKYg66YNE3mfhGla0uB2k4ugVtH0ePd/view
http://www.cwma.org/Muskthistle.html

Origin/Habitat ⁷

Plumeless Thistle is native to Europe and Asia. In Colorado it is a highly competitive weed which invades disturbed areas, pasture, rangeland, forest land, cropland, recently burned areas, and waste areas. It occurs in all soil types so long as they are well-drained, but establishes best on bare soil and in small shallow cracks. It can form extensive dense stands and may produce allelopathic chemicals that inhibit desirable plant growth.

Source:
https://drive.google.com/file/d/1BxKYg66YNE3mfhGla0uB2k4ugVtH0ePd/view
http://www.cwma.org/Muskthistle.html

Sources and Credits

1. (c) Jon Sullivan, some rights reserved (CC BY), http://www.flickr.com/photos/16921893@N00/7780004540
2. (c) Matt Lavin, some rights reserved (CC BY-SA), http://commons.wikimedia.org/wiki/File:Carduus_nutans_(5841906493).jpg
3. (c) Chuck Sexton, some rights reserved (CC BY-NC), uploaded by Chuck Sexton
4. (c) Matt Lavin, some rights reserved (CC BY-SA), http://commons.wikimedia.org/wiki/File:Carduus_nutans_(5841904841).jpg
5. (c) Stefan.lefnaer, some rights reserved (CC BY-SA), http://commons.wikimedia.org/wiki/File:Carduus_nutans_sl1.jpg
6. Adapted by Colorado Parks and Wildlife from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Carduus_nutans
7. (c) Colorado Parks and Wildlife, some rights reserved (CC BY-SA)

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