Plant Identification needed

This plant has grown 3 to 4 ft. in 3 months. Does anyone know what it is please?

 

It looks like Himalayan Balsam

 

Thank you for replying. I will now look your suggestion up and compare it with my plant.
It came up by itself and as it looked interesting I have let it grow. If it gets any taller perhaps Kew Gardens will collect it, although their big tropical green house has now been emptying to all renovation of the ancient structure. Kind regards Leafy Lady

 

MONDAY I have followed your reply by going to R. Horiticultural Soc. web. They say it is an invasive plant and each one can produce 100s of seeds, In fact I have seen it beside the River Mole in Surrey, it is v. pretty. Alas I have to uproot it and dispose before it grows flowers, pity because it is a splendid looking plant. Thank you so much for your guidance. My Good
Wishes to you.

Leafy Lady.

 

It's taken over huge swathes of water meadows along the River Wey, its here to stay too late to start pulling it up.

Ironically, here in Somerset, its getting displaced by Rapeseed escapees.

 

Thank you for your interesting comment. I am just going out to garden to dig this handsome plant up. It hasnt flowered so I have contained it. Best wishes. Leafy Lady

 

Tis a shame, but I had one plant in my garden once, next year there were hundreds, they've got edible explosive seed pods, they pop in the heat of your mouth when you eat them.