Orange hawkweed2017-07-24T20:00:30+00:00

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.

Historical

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.

Back to Weed List

Photos courtesy of La Plata County