(Carduus acanthoides L. )
Life Span: Biennial (or winter annual)
This plant is less common as the Musk Thistle, but has the potential to become just as widely spread. It is found mostly in Idaho, Wyoming, and Colorado, but infestations are growing in Nebraska, especially in the Northeast. The Plumless Thistle was also introduced as an ornamental from Eurasia in the mid 1900’s.
The reason this plant is considered noxious is:
1. Each plant generates thousands of seeds.
2. There are no natural predators for the plant in America.
3. It is aggressive.
4. Negative impact on Agriculture.
This plant looks very similar to the Musk Thistle, especially when it is away from a Musk Thistle. These are it’s different aspects:
1. It looks like a thin Musk Thistle, only getting about 4 feet tall.
2. Thorns go all the way to the blossom.
3. The blossom is much smaller.
4. The leaves are deeply serrated to nearly the Midrib and are a solid green color.
For a more detailed description of Plumeless Thistle, check out the Nebraska Weed Control Association Website.