What is the species?
- Impatiens glandulifera (policeman’s helmet)
- ODA “B” rank
Policeman’s helmet is native to India and the Himalayas, and is now common along the north Oregon coast.
Why are we concerned?
Policeman’s helmet is known to form dense patches that begin in open, disturbed areas, and particularly along streams. Policeman’s helmet infestations can lead to:
- Reduced plant and animal diversity as other species are choked out
- Increase in streambank mass wasting, landslides, and erosion
How does it spread?
Policeman’s helmet is primarily spread by seeds, but it is also capable of rooting wherever the stem touches soil. Policeman’s helmet seeds are moved around by:
- Running water
- Hiking boots
- Nursery trade
What does it look like?
Policeman’s helmet can be over 6 feet tall, unknown in native impatiens species. At the back of the magenta to pink flowers, a short nub of a spur is bent over against the body of the flower (see photo). Leaf edges will be fairly to dramatically toothed. Seedpods will explode when dry, scattering seed in all directions.
Are there any lookalikes?
There are many species and varieties of impatiens. The most likely to be confused with policeman’s helmet is Himalayan balsam (Impatiens balfourii), which itself is a species of concern. I. balfourii tends to have a longer, straighter spur than I. glandulifera, flowers ranging with white and purple petals (not pink), and shorter plants (3 feet tall or shorter).
How do we deal with it?
- Manual: As an annual, handpulling before policeman’s helmet sets seed works well for managing populations.
- Herbicide: Populations in Portland have been small enough not to require herbicide use.
How can folks help?
If you suspect you’ve found policeman’s helmet, call either the city of Portland or leave a report on the hotline. Policeman’s helmet should be positively identified before management is attempted, to prevent unintended damage to related native species.