Aliens taking over the UK

Himalayan Balsam (Impatiens glandulifera)

Himalayan Balsam (Impatiens glandulifera) is another horticultural specimen that was introduced in the 19th Century, 1839 to be precise that has since escaped to become nuisance in the wild.
What is this stuff which is invading all areas even woodland paths as seen here killing all other plants underneath it ! Its the Alien Invasive species Himalayan Balsam
It is the tallest annual in the UK growing up to 3 metres and is an attractive plant with a distinctive purple pink flower.
Each plant can produce up to 800 seeds which are explosively released when the seed pods are mature, capable of projecting the seeds 7 metres. This is a highly effective dispersal method which enables the plant to rapidly colonise the damp and riparian habitats that the plant favours. The seeds may be further spread by water and can remain viable for 2 years.