Policeman’s Helmet

Policeman's Helmet

Scientific name: Impatiens glandulifera

Common names: Policeman’s helmet, jewelweed, Himalayan balsam

Description: Policeman’s helmet is an invasive annual that is best adapted to moist and riparian areas. Originally from Asia, it has been brought to North America as an ornamental. Typically germinating in early Spring, it displays its purple, white, or pink flowers from June through October. The stems of Policeman’s helmet are hollow, its egg-shaped to oblong leaves have serrated edges, and it can grow up to 10 feet tall.

Impact: Policeman’s helmet is a prolific reproducer. One plant can produce up to 800 seeds, which can persist in the environment for 18 months without losing the ability to germinate. The seeds can even sprout underwater! As a plant that often grows near water, its seeds are easily transported downstream through ditches and streams. Due to its height, ability to grow in dense thickets, and large leaves, it is able to outcompete native riparian plants, thereby negatively impacting the habitat for local wildlife. Further, its ability to root in fast moving water can result in changes to stream hydrology, potentially increasing the risk of flooding or erosion. If you suspect Policeman’s helmet is on your property, please contact our office at 503-325-4571.

Source: KingCounty.gov

For more information, please visit the Noxious Weed resources at KingCounty.gov: http://www.kingcounty.gov/services/environment/animals-and-plants/noxious-weeds/weed-identification/policemans-helmet.aspx