Himalayan Balsam Impatiens glandulifera
Himalayan balsam is an annual herb, native to the western Himalayas. In the early 1800s it was introduced to many parts of Europe, New Zealand and North America as a garden ornamental. Himalayan Balsam has an orchid shaped flower resembling a British policeman’s helmet, which gave rise to its other common name of “Policeman’s helmet”.
Himalayan balsam can completely cover an area and crowd out native vegetation. Mature seed capsules explode when touched and can eject seeds as much as 5 m from the parent plant, giving it the alternate common name of “Touch-Me-Not plant”. It is mostly found in riparian areas, especially river edges and wetlands.
For more information, go to http://www.invadingspecies.com/invaders/plants-terrestrial/himalayan-balsam/