- Naked Weed
- Gum Succory
General: Rush Skeletonweed is a perennial that is considered noxious under the BC Weed Control Act.
Flowers: Each flower head contains 10 – 12 strap-shaped, bright yellow petals. They occur individually or in groups of 2 – 3. The flowers are 1.5 cm in diameter and are flat across the end with distinct lobes or teeth.
Stem: Mature plants range from 0.4 – 1.0 m in height. The base of the stem is coarse with downward pointing brown hairs. The stem is highly branched with few leaves, and broken stems exude a latex sap.
Leaves: The leaves are coarsely lobed with fine dense hair on both sides and sharp spines on the margin. The leaves on the stem are narrower than the basal leaves.
Fruit: The seeds are pale brown to nearly black achenes with a white pappus (cluster of hairs).
Roots: Deep, extensive taproot system. Roots can reach 2 m deep.
Skeletonplant (Lygodesmia juncea) has pink, occasionally white, flowers and grows in the southern interior of BC.
Habitat and Origin
Rush Skeletonweed is native to Europe and Asia. It was initially reported in Washington in 1938 and was suspected to have been introduced as a contaminant of livestock fodder.
Rush Skeletonweed generally prefers well-drained and light-textured soils. It is best suited to areas with mild winters and warm summers. Rush Skeletonweed can be found in fallow and abandoned fields, along roadsides, and in disturbed areas.
Propagation & Vectors of Spread
Rush Skeletonweed spreads through both seed and vegetative methods. A single multi-stemmed plant can produce as many as 20,000 seeds. Rush Skeletonweed can form new genetically-identical plants from root fragments.
Rush Skeletonweed produces parachute-like seeds that travel easily by wind and water. Local dispersal generally takes place by root fragments which can grow into new plants. Rush Skeletonweed can also be spread by animals, humans, as well as in contaminated soil and seed mixes.
Ecological and Economic Impacts
- Forms dense monocultures, reducing biodiversity.
- Reduces livestock and wildlife forage.
- Stems can cause damage to harvest machinery.
- Contaminates wheat crops.
What Can I Do?
Rush Skeletonweed is currently found in Pemberton, but not in Whistler or Squamsih, so PREVENTION of further spread is key.
Learn to identify Rush Skeletonweed: use the images presented in this profile page to learn how to identify Rush Skeletonweed
What to do if you spot it: You can report any Rush Skeletonweed sighting by clicking here.
- Regularly monitor properties for weed infestations.
- Ensure soil and gravel are uncontaminated before transport.
- Check wildflower mixes to ensure that they do not contain Rush Skeletonweed.
- Ensure plants (particularly flowering heads or root fragments) are bagged or covered to prevent spread during transport to designated disposal sites (e.g., landfill).
- Do not unload, park or store equipment or vehicles in infested areas; remove plant material from any equipment, vehicles or clothing used in such areas and wash equipment and vehicles at designated cleaning sites before leaving infested areas.
- Do not plant Rush Skeletonweed in a garden, no matter how well-contained its enclosure may seem.
- Do not move soil that has been contaminated with Rush Skeletonweed.
- Do not compost!
- Regular mowing/tilling can prevent seed formation and deplete root energy reserves.
- Small infestations can be hand-pulled but the operation will need to be repeated, as any root fragment left behind will re-sprout.
- Any plant parts removed should be bagged and taken to a landfill.
- Herbicides should be applied after the plant has bolted but before it sets seed.
- Repeated applications of a mixture of glyphosate and dicamba has proven effective; clopyralid and dicamba mixes have also been used to control Rush Skeletonweed.
- Lastly, picloram has been effective when applied to rosettes, but it is not suitable for wet, coastal soils.
- We recommend that any herbicide application is carried out by a person holding a valid BC Pesticide Applicator Certificate. Before selecting and applying herbicides, you must review and follow herbicide labels and application rates; municipal, regional, provincial and federal laws and regulations; species-specific treatment recommendations, and site-specific goals and objectives.
Some biological agents exist, including root-feeding moth (Bradyrrhoa gilveolella), gall-forming mite (Eriophyes chondrillae), leaf & stem rust (Puccinia chondrillina, Puccinia acroptili), and stem gall wasp (Aulacidea acroptilonica)
- Alberta Invasive Species Council, Rush Skeletonweed, https://abinvasives.ca/wp-content/uploads/2017/11/FS-RushSkeletonweed.pdf
- Canadian Food Inspection Agency, Weed Seed: Chondrilla juncea (Rush Skeletonweed), https://www.inspection.gc.ca/plant-health/seeds/seed-testing-and-grading/seeds-identification/chondrilla-juncea/eng/1475881505959/1475881506298
- Fraser Valley Invasive Species Society, Rush Skeletonweed, https://fviss.ca/invasive-plant/rush-skeletonweed
- Government of BC, A Guide to Weeds in British Columbia: Rush Skeletonweed, https://www2.gov.bc.ca/assets/gov/environment/plants-animals-and-ecosystems/invasive-species/alerts/rush_skeletonweed.pdf
- Invasive Plant Atlas of the United States, Rush Skeletonweed, https://www.invasiveplantatlas.org/subject.html?sub=4404
- Invasive Species Compendium (CABI), Chondrilla juncea Rush Skeletonweed, https://www.cabi.org/isc/datasheet/110385
- Invasive Species Council of BC, Rush Skeletonweed, https://bcinvasives.ca/invasive-species/identify/invasive-plants/rush-skeletonweed#:~:text=Rush%20skeletonweed%20(Chondrilla%20juncea)%20is,Kimberley%2C%20Windermere%2C%20and%20Creston
- Invasive Species Extension, Chondrilla juncea Rush Skeletonweed, https://invasive-species.extension.org/chondrilla-juncea-rush-skeletonweed/
- Techline Invasive Plant News, Rush Skeletonweed Management: Challenges and Solutions, https://www.techlinenews.com/articles/2014/rush-skeletonweed-management-challenges-and-solutions
- United States Department of Agriculture, Rush Skeletonweed, https://plants.usda.gov/plantguide/pdf/pg_chju.pdf