Policeman's Helmet
Impatiens glandulifera
Washington State Classification
Class B — Control Required (Designated)
It is considered extremely invasive to moist, natural areas.
Required control in Region 1 (all western Washington counties)
Quick Reference
Identification
Growth Habit
Policeman's helmet is an herbaceous annual that is succulent and glabrous (smooth and hairless), and it can range from 3 feet to 10 feet tall.
Leaves
Leaves are alternate, opposite or whorled and usually have 3 leaves to a node. The shape is oblong to ovate to elliptic. They are about 6 inches long and half as wide with sharply toothed margins.
Flowers
Flowers are irregular and the color ranges from white to all shades of pink purple. They have 5 petals (2 fused), 3 sepals (2 fused), and 5 stamens. The shape resembles a British policeman's hat, hence the common name.
Fruit & Seeds
Flowers form capsules that contain small seeds (3 mm).
Impact
It is considered extremely invasive to moist, natural areas. Introduced and sold as an ornamental, this species escaped with distribution primarily in lowland riparian areas which include moist forests, stream sides and roadside thickets.
Ecology & Spread
Habitat
Policeman's helmet is partially shade tolerant and is found in lowland, riparian areas which include moist forests, stream sides and roadside thickets. Please click here to see a county level distribution map of Policeman's helmet in Washington.
Spread Mechanisms
Reproduction
Policeman's helmet reproduces by seed. Each plant can produce up to 800 seeds. The seeds are ejected over 20 feet from the capsule. Seeds can germinate underwater and can be viable for 18 months or more.
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Control Methods
Mechanical
- An annual with a shallow root system, this plant pulls up easily. A seed bank is present with 2 year viability - follow up control is recommended. Populations may be mowed but need to be monitored in case mowed plants resprout later in the season. Remove and carefully dispose of flower and seed heads prior to mowing.