Synonyms: Pilosella aurantiacum
Common names: orange hawkweed
Hieracium aurantiacum (Orange hawkweed) is an herbaceous perennial forb that reproduces by seed, rhizomes, and stolons. It is native to northern and central Europe and is common along roadsides, meadows and in forest understories. Once established, Hieracium aurantiacum can spread quickly, excluding native species. It was introduced in 1875 to the US in Vermont as a garden ornamental, was marketed for its attractive orange flowers for a long period, and has since repeatedly escaped cultivation. This plant is listed as a noxious weed in the western US in Colorado, Idaho, Oregon, Montana, and Washington.
Cal-IPC Rating: Watch
CDFA Rating: B?
Plant Risk Assessment
Plant Risk Assessment- An evaluation of the potential for a plant to be invasive in California.
Weed Management NotesNo Weed RIC Management Notes are available for this species. Check for information on other species in the genus on the Weed RIC site.
Cal-IPC Newsletter Articles
- Inventory Update 2022. Burger, Jutta. Vol 30, Issue 1
- Hawai’i: Ground zero for plant invasions - and EMAPi13!. Darin, Gina. Vol 23, Issue 3
Cal-IPC Symposium Presentations
Presentations are linked where available. Where a presentation is not available, find more information by reading the abstract in the Cal-IPC Symposia Archive.
- 2019 Weed Alerts. Burger, Jutta; Price, Bob (2019)
Other Hieracium aurantiacum Information
- Bugwood - National database from the Center for Invasive Species and Ecosystem Health at the University of Georgia.
- CalPhotos - Images of plants taken mostly in California.
- Calflora - Distribution map and records of this species in California.
- EDDMapS - Distribution of this species in North America.
- GBIF - Global distribution information.
- Jepson Interchange - Information on this plant's taxonomy, biology, and distribution from UC Berkeley's Jepson Herbarium.
- USDA PLANTS Database - Information on identification and distribution, with links to websites in individual states.
- The Plant List - Global taxonomic resource and collaborative clearinghouse from Kew Gardens, the Royal Botanic Gardens, the Missouri Botanic Garden and others.