Originating from the Himalayan mountains, the Himalayan balsam (Impatiens glandulifera) has settled in a bit too well in Helsinki. Nowadays it is considered an invasive alien species, which displaces native species as it spreads, thus reducing natural biodiversity.
The Himalayan balsam is believed to have escaped from garden plantings by hitching a ride in garden waste dumped into the environment and with the help of its seed pods, which explode when disturbed, launching seeds up to seven metres away. This has allowed the Himalayan balsam to spread to large areas. It is destroyed by weeding.
Photo Jussi Helimäki