Orange Hawkweed
Hieracium aurantiacum
Washington State Classification
Class B — Control Required (Designated)
It's an aggressive, unpalatable competitor of pasture and range plant species, crowding out more desirable forage.
Required control in Region 1 (all western Washington counties)
Quick Reference
Identification
Growth Habit
Orange hawkweed is a perennial that has fibrous roots and rhizomes. Its flowering stems grow 7.9 inches to 35.4 inches (20 to 90 cm.) tall. It exudes a milky sap when injured.
Leaves
Leaves all basal except for one or two stem leaves. Basal leaves with a rounded to narrowly rounded blade that tapers in at the base. They are generally 3 to 5 (or more) times longer than wide. Basal leaves with hairs on both sides.
Flowers
Flowerheads in compact to open clusters of 3 to 7 (to 12+). Flowerheads are showy, red on the margin with an orange center, 1 inch in diameter and composed of all ray flowers. Bracts at the base of flower heads with various types of hairs.
Fruit & Seeds
Achenes (seeds) with white bristles (pappus).
Impact
It's an aggressive, unpalatable competitor of pasture and range plant species, crowding out more desirable forage. It is a serious pest of lowland pasture, mountain meadows and lawns. It’s sold as an ornamental plant in nurseries.
Ecology & Spread
Habitat
Orange hawkweed occurs in meadows, grasslands, rangelands and pastures. Please click here to see a county level distribution map of orange hawkweed in Washington.
Spread Mechanisms
Reproduction
Orange hawkweed reproduces by seeds, stolons and rhizomes.
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Control Methods
Mechanical
- Small infestations may be dug out, being careful to remove all plant parts.
Cultural / Prevention
- Careful digging is useful to manage weed populations. However, digging can carry undesirable weed seed to the surface and foster further germination.