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Home>Plant Species>Weed Species>Rush skeletonweed

Drawing of rush skeletonweed Rush skeletonweed
Chondrilla juncea

question markDid you know?

Juvenile rush skeletonweed plants can resemble a dandelion!

How did rush skeletonweed get here?
Rush skeletonweed is thought to have originated in the region surrounding the Caspian Sea. It was apparently introduced to eastern North America in contaminated seed or with animal bedding around 1872. It was not noticed in the Great Basin until the 1960’s. At that time, Oregon traced the majority of their rush skeletonweed infestations to a single gravel pit. Only the northern portions of the Great Basin are infested with this weed, but it continues to expand its range.

What are its characteristics?
Rush skeletonweed is a perennial forb that reproduces by seed as well as through lateral roots that send new shoots to the soil surface. Rush skeletonweed flowerIf roots are broken up, a single root section less than 1 inch long is capable of producing a new plant. Seedlings establish best in sandy, well-drained soils. In the rosette stage, rush skeletonweed can resemble a dandelion. At maturity, this plant grows up to 36 inches tall and appears to be all stems. The stems are green and finely grooved, with only small triangular leaves on the upper branches. Small yellow flowers appear in late June through September. Seed production is between 500 and 1,500 seeds per plant, and seeds have little or no dormancy. A unique attribute of rush skeletonweed is that stems and leaves contain a white latex sap that has been investigated as a possible source of rubber.



Why is rush skeletonweed a problem in the Great Basin?rush skeletonweed plant
When rush skeletonweed plants are injured, new growth may be produced almost anywhere on the remaining root system and give rise to new rosettes. Infestations impact the cattle industry when rush skeletonweed displaces more beneficial forage species. Rush skeletonweed successfully out-competes native species for limited resources, particularly nitrogen. The ability of this species to resprout following disturbance allows rush skeletonweed to survive fires and become more dominant.

How can we fight this weed?
Rush skeletonweed is difficult to control in some situations. Biological control agents have been shown to reduce plant health. Small infestations can be eradicated with herbicides. See the Weed Management Handbook on the University of Wyoming Extension website for up-to-date application information.

Large, dense populations are more difficult to control and require a long-term plan that should include containment of current populations. Driving vehicles through rush skeletonweed-infested areas during the seeding period should be avoided. Rosettes are palatable to cattle and sheep. Continuous grazing keeps plants in the rosette stage during the summer months when little other green forage is available. Livestock grazing on infested ranges should be transported to a holding area for 10 to 14 days before being moved to other areas.

Images:
-Drawing: USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913. Illustrated flora of the northern states and Canada. Vol. 3: 314.
-Flower: Intermountain Herbarium.
-Plant: USDA APHIS Archives, USDA APHIS, (http://www.forestryimages.org).

Text references:
-USDA, NRCS. 2006. The PLANTS Database (http://plants.usda.gov, 26 September 2006). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.
-Washington State Noxious Weed Control Board. Written Findings of the State Noxious Weed Control Board. Available: (http://www.nwcb.wa.gov/weed_info/Chondrilla_juncea.html, 27 September 2006).
-Whitson, T. D., et.al. 2000. Weeds of the West., 9th ed. Western Society of Weed Science, Newark, CA.
-Zouhar, Kris 2003. Chondrilla juncea. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: (http://www.fs.fed.us/database/feis/, 26 September 2006).