• Mature, vigorous plants can produce 1,500 flower heads, with the capability of producing 20,000 seeds.
• Each seed has a pappus, which is capable of carrying seeds along wind currents up to 20 miles.

Rush skeletonweed also spreads by shoot buds found along lateral roots, and from shoot buds found
near the top of the main tap root:

• Vegetative spread is also possible when a root fragment, as deep as 4 feet down, is left in the ground.
• When the plant stem or root is mechanically injured, vegetative growth is initiated.

Where does it grow?

What is the distribution in Washington State?

Click map to enlarge.

• Rush skeletonweed has been documented in several counties, refer to map for distribution levels in specific counties.
• Distribution map is based on 2003 data.

How do I control it?

General control methods:  Research found that an integrated approach using both plant competition and biological control agents often results in better control then either method used separately. Herbicide control may vary depending on the biotype of Rush skeletonweed.

Cultural: Using beneficial forage species for competition, will not suppress the dominance of Rush
skeletonweed. Continual grazing decreased populations, while rotated grazing increased populations.

Herbicide: Please refer to the PNW Weed Management Handbook, or contact your county noxious weed coordinator.

Mechanical: Mechanical methods stimulate growth.

Biological:

• The gall midge (C. schmidti) was introduced to California in 1975, and is established throughout
  the Pacific Northwest. The gall midge impacts the rosette and flowering stems of all biotypes in
  this region, affected stands are often a noticeable purple to reddish color.

• The rust fungus, P. chondrillina, was introduced to Washington in 1978. Two biotypes, the early-flowering biotype in Washington and Idaho, and the late-flowering biotype in Oregon are resistant to this rust.

• A gall mite (Eriophyes chondrillae) was introduced to Washington in 1979, and it is considered the
  most effective biological control agent available, to date. This mite is effective against all biotypes
  of rush skeletonweed. The visible impacts to flowering buds are leaf-like galls, up to 2” in
  diameter, which can reduce or prevent seed production.

Are there plants that may be confused with Rush skeletonweed?

There are hundreds of biotypes of Rush skeletonweed, they are sometimes differentiated by leaf morphology, height, branching patterns or flowering times, making identification difficult. The rosettes may be mistaken for  common dandelion (Taraxacum officinale ) rosettes. If you need help with plant identification, please contact your county noxious weed coordinator.

For more information