Orange hawkweed (Hieracium aurantiacum)

Common Names: Orange paintbrush, red daisy flameweed, devil's weed, grim-the-collier

Description: Introduced to North America as an ornamental for desirable flame-colored flowers.

Habit: Fibrous rooted perennial, grows 10-36 in tall and branching at the top to produce flowerheads.

Leaves: Simple, basal, 1-2 leaves measuring about 4.5 in long, covered with hairs.

Stems: Erect, does not have stem leaves, contain a milky juice and are covered with stiff hairs.

Flowers: Conspicuous, orange-red in color, ray flowers, 5-35 flowerheads; blooms June through September.

Fruit and seeds: Each flower produces 12-30 tiny seeds that are dark brown or black in color, cylindrical, elongated, longitudinally ridged, barbed and bristled. Dispersed by wind, water, or "hitch-hiking". Viable in soil for up to 7 years.

Habitat: Native to Europe. Found in urban sites, moist meadows, pastures, hay fields, roadsides, gravel pits, forested areas, tree plantations and riparian areas.

Reproduction: By seed and vegetatively. Roots are shallow and fibrous with aboveground stolons and below ground rhizomes that allow for aggressive vegetative reproduction. Stolons originate from buds in the rosette when plants flower. Runners radiate out from the original plant and form new rosettes when they touch down and take root.

Similar species: Meadow Hawkweed (Hieracium caespitosum); Tall Hawkweed (Hieracium piloselloides).

Monitoring and rapid response: Mowing reduces seed production, but encourages vegetative spread. Hand pull or dig up small infestations, removing roots and rhizomes. Effectively controlled using any of several readily available general use herbicides such as 2,4-D or dicamba before bloom.

Credits: The information provided in this factsheet was gathered from the U.S. Department of Agriculture, Forest Service.

Individual species images that appear with a number in a black box are courtesy of the Bugwood.org network (http://www.invasive.org).Individual photo author credits may not be included due to the small display size of the images and subsequent difficulty of reading the provided text. All other images appear courtesy of Google (http://images.google.com).

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