Opportunist 2

I am sure that most of us are familiar with the highly successful invader known as Himalayan Balsam.  I think it produces pretty swathes of mainly pink flowers, but I do wish it had not invaded. 
I remember coming across this around 60 years ago, and being fascinated by how far the seeds might fly when we fired the ripe seed heads. Not anymore though! Better to remove the new shoots than wait for the pretty flowers.