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Species
Information
- orange
hawkweed
- Hieracium
aurantiacum
L.
- USDA
Symbol: HIAU
- Oregon
Noxious Weed Designation: A, T
- Pictures
ALERT: PLEASE CALL 1-866-INVADER IF YOU SUSPECT YOU HAVE FOUND THIS SPECIES
Identification: Perennial; flowers in May and June. Grows up to 12 inches. Leaves hairy, spatula shaped and almost exclusively basal. Flower heads red to orange, 1/2 inch wide and number up to 30 per plant. Reproduces extensively by stolons which form dense mats of vegetation.
Impacts: This plant inhabits moist grasslands and forest openings. It is a serious weed of lawns, pastures and roadsides. Gardeners find the brilliant orange color appealing. This plant’s aggressive growth derives from its ability to spread by rhizomes, stolons or seeds, and its allelopathic compounds practically eliminate all other vegetation in older stands. It is not uncommon to find this species mixed with other hawkweeds in new infestations. Wilderness areas in the Pacific Northwest are at risk of invasion.
Biological
Controls: Biological control agents are not used on "A" listed weeds in Oregon. This weed is being managed for eradication or containment.
Oregon
Maps of Orange Hawkweed Distribution
Links:
USDA
Plants Database information on orange hawkweed
GRIN
Database information on orange hawkweed
Oregon Department
of Agriculture information on orange hawkweed
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