Chondrilla juncea, Rush Skeletonweed

Gardens & Landscapes, Invasive Species, Extension Master Gardener November 13, 2015 Print Friendly and PDF

Invasive Species: Chondrilla juncea, Rush Skeletonweed

Rush skeletonweed is an invasive perennial forb that can grow up to 4 ft. (1.2 m) tall. Coarse-looking, multiple stems appear leafless due to inconspicuous leaves and arise from a basal rosette of sharply lobed leaves. The lower 4 to 6 in. (10.2 to 15.2 cm) of stem is covered with coarse brown hairs. Both stem and leaves produce a milky sap when broken. Flowers are small and yellow and develop in the midsummer to fall. Mature, healthy plants can produce 1,500 flower heads and up to 20,000 seeds. Rush skeletonweed invades dry rangelands in the western United States, displaces native species, and reduces forage for livestock and wildlife. Rush skeletonweed is native to regions of Europe, Asia, and Africa and was accidentally brought to the United States as a contaminant of fodder in 1914.

What are invasive species and why should we be concerned about them? 


Taxonomy: Scientific and Common Names for This Species

Asterales > Asteraceae > Chondrilla juncea L.

Synonym(s): skeletonweed

Chondrilla juncea - USDA PLANTS Profile

Distribution Maps

Rush skeletonweed - The reported distribution of this invasive species across the United States. (Source: Invasive Plant Atlas of the United States)

Up-to-the-minute distribution maps and why they are important

Reporting This Invasive Species

What is the best way and place to report the occurrence of an invasive species? 

 How to report an invasive species sighting to EDDMapS - Early Detection & Distribution Mapping System

EDDMapS - Report an invasive species to EDDMapS

Cooperative Extension Offices - Find your local Cooperative Extension office on this map provided by USDA

How to Identify

This invasive species can be identified by looking for the characteristics described in the paragraphs that follow.

Plant

Rush skeletonweed is an invasive perennial forb that can grow up to 4 ft. (1.2 m) tall.

rush skeletonweed (Chondrilla juncea) rush skeletonweed (Chondrilla juncea)
Gary L. Piper, Washington State University, bugwood.org Joseph M. DiTomaso, University of California-Davis, bugwood.org

Foliage

Coarse-looking, multiple stems appear leafless due to inconspicuous leaves and arise from a basal rosette of sharply lobed leaves. The lower 4 to 6 in. (10.2 to 15.2 cm) of stem is covered with coarse brown hairs. Both stem and leaves produce a milky sap when broken.

rush skeletonweed rush skeletonweed (Chondrilla juncea)
Joseph M. DiTomaso, University of California-Davis,   bugwood.org Eric Coombs, Oregon Department of Agriculture, bugwood.org

Flower

Flowers are small and yellow and develop in the midsummer to fall.

rush skeletonweed rush skeletonweed (Chondrilla juncea)
Utah State University Archive, Utah State University bugwood.org Eric Coombs, Oregon Department of Agriculture, bugwood.org

Fruit

Mature, healthy plants can produce 1,500 flower heads and up to 20,000 seeds.

rush skeletonweed (Chondrilla juncea) rush skeletonweed
Joseph M. DiTomaso, University of California-Davis,   bugwood.org Steve Hurst, USDA NRCS PLANTS Database, bugwood.org

Native Species That Resemble Rush Skeletonweed

 

- Images at invasive.org

   
bugwood.org bugwood.org

 

- Images at invasive.org

   
bugwood.org bugwood.org

 

Additional Images for Rush Skeletonweed

Rush skeletonweed - Images at Invasive.org

 

Learning Resources for Rush Skeletonweed

 

Additional Information, Biology, Control and Management Resources

Control and management recommendations vary according to individual circumstances. Location, habitat, weather, and a variety of other conditions are factors that help determine the best treatment choice. To find the safest and most effective treatment for your situation, consult your state's land-grant institution. If you will use chemicals as part of the control process, always refer to the product label.

United States Land-Grant University System - Find your land-grant university's College of Agriculture, Cooperative Extension Service, or other related partner on this map provided by USDA.

Weed of the Week - USDA Forest Service

Chondrilla juncea - Flora of North America

Noxious Weeds - King County

Rush Skeletonweed - California Department of Food and Agriculture

Plant Profiles - Cal-IPC

Fire Effects Information System - USDA Forest Service

Jepson Herbarium - University of California


 

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This work is supported by the USDA National Institute of Food and Agriculture, New Technologies for Ag Extension project.