It's very pretty, whatever it is. Unfortunately I can't see the flowers properly. Could it be some form of persicaria?
It might be a kind of polygonum.
Might be this one. Persicaria (formerly Polygonum) campanulata (um)
Possibly Persicaria wallichii
Thank you nutcutlet, that's the one!
i like the look of that one, what sort of soil is it growing in? I'm a bit dry here but have found places that other persicaria do OK in
cant quite make out the flowers but the leaves look like that invasive plant found on river banks etc think it is called hymilayan or indian Balsam. if it is get rid of it as it spreads like mad dont compost it either bin or burn as the seeds are very resiliant or pieces of it will grow new roots. It is getting to be a nightmare for conservationists and farmers. hopefully it will get on the banned list soon.
i cansee what you mean trifid but Becky's plant isn't any sort of balsam.