CWMA

PO Box 419

Hotchkiss, CO 81419

 

970-361-8262

fax: 720-880-3051


Email:contact@cwma.org

 

 

Orange hawkweed

Hieracium aurantiacum

 

Keys to Identification

  • Orange hawkweed is a perennial member of the Sunflower family (Asteraceae)
  • It likes moist grassy areas and can be found along creeks, in meadows, and along rights-of-way
  • Reproduces by runners and by seed
  • Each bright orange flower is between 1/2 to 1 inch wide. They are grouped at the top of a slender stem and tend to close up when it is shady, making the plants difficult to see
  • Hairy leaves are found at the base of the plant
  • Orange hawkweed is found in only a few places in Colorado and is on the A List, requiring eradication

This information courtesy of the Colorado Natural Areas Program

 

Family: Sunflower (Asteraceae)

 

Other Names: Devil's paintbrush

 

USDA Code: HIAU

 

Legal Status: Colorado Noxious Weed List A

Notify your county weed supervisor if you find this plant!

 

 

Identification

Lifecycle: Perennial

 

Growth form: Forb

 

Flower: Orange in groups of up to 13 at the end of stem. June-July.

 

Seeds/Fruit: With papus

 

Leaves: Basal. Dark green hairy.

 

Stems: Fine, leafless. 1-2 ft tall with stiff hairs

 

Roots: Fibrous spreading with stolons at nodes

 

Seedling: Seedling leaves have bristly hairs

 

 

Similar Species

Exotics: Yellow hawkweed

 

Natives: Native hawkweeds and false dandelion

 

 

Impacts

Agricultural: Infests hay fields, animals will not feed

 

Ecological: Forms mats that prevent other plants from growing

 

 

Habitat and Distribution

General requirements: Likes shady areas. Can be found in grassy areas, moist pastures, stream banks.

 

Distribution: Found in a number of counties in Colorado in small populations. Also found throughout northern US

 

History: Native to Europe

 

Biology/Ecology

Life cycle: Perennial plants form rosettes in spring and early summer, spread primarily through stolons. Plants flower in June-July

 

Mode of reproduction: Seed, stolons, rhizomes

 

Seed production: Each stem may produce thousands of seeds

 

Seed bank: Not known

 

Dispersal: Wildflower seed mixes, wind, water and possibly animals

 

 

 

References

Callihan, R.H., L.M. Wilson, J.P. McCaffery, T.W. Miller, 1997. Hawkweeds. Pacific Northwest Extension Publication 499. Cooperatively published by the University of Idaho Cooperative Extension, Oregon State Cooperative Extension Service, Washington State Cooperative Extension and the U.S. Department of Agriculture.

 

Hoffman, R. & K. Kearns, Eds.. 1997. Wisconsin Manual of Control Recommendations for Ecologically Invasive Plants. Wisconsin Dept. Natural Resources. Madison, Wisconsin.. 102pp.

 

Whitson, T.D. (Ed.) et al.. 1996. Weeds of the West. Western Society of Weed Science in cooperation with Cooperative Extension Services, University of Wyoming. Laramie, Wyoming. 630pp.

 

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