mystery plant help me identify

Looks like an Acanthus but that has a flower spike with lots of white/lilac flowers growing up it.

Not sure what it is, but it doesn't look like anything you want to keep - I'd wait for it to die back in the autumn, then dig up the root.

I have found out from Wikipedia- It's a "Datura" probely Stranonium-CAUTION extremely Poisonus,I had thought so. common names:- Jimson weed-Thorn apple-Devils cucumber, I thought it looked "evil"

Which is why I said I'd wait till it had died down and then dig it out - wouldn't want to have skin contact, and by the time it dies back, it'll be cold enough to wear a coat and gloves...

Yes, it's definitely a Thorn Apple (Datura stramonium). That branching habit is quite characteristic, as are those leaves. The flowers (can't quite make them out sit between the fork of two branches. The flowers are followed by a spiny seed capsule.

And if you wait until it has died down - those spiny seed capsules will have split and sent their seed all over the place....and the plant will be back with vengeance next year!

Wow! Lucky you! unless you've got kids or pets. The genus was derived from "datura", an ancient Sanskrit word for the plant. Stramonium is originally from Greek, strychnos (nightshade) and manikos (mad). Cautionary tale follows:

A mate of mine whilst backpacking in India, came across (met is the wrong word) a fellow European traveller who my mate was told by the locals, had been smoking Datura with the saddus' "holy men" a few days earlier. This traveller was totally loco, babbling, laughing and crying, totally naked, covered in and eating his own poo. Didn't know who he was, didn't know how he got there. Couldn't string a sentance together. What a mess. My mate thought he'll sleep it off and be ok in a couple of days.
However, when my mate returned to the village three months later, the traveller was still mad! My mate took him to the hospital and informed the travellers parents.
Moral: Don't eat, drink or smoke Datura.
Looks nice and has a nutty smell though.
Nuff said.
check my photos for a datura in full flower.

many thanks to all who put in suggestions, as you can see I found out what it is from Wikkie poisonous plants-steer clear, unless you want to end up as in Stjohnstongue comments above. The Navajo have a neat saying about this plant:- Eat a little and go to sleep, eat some more and have a dream, eat a little more and don't wake up!
I think that says it all-subject is now closed, I must go- feeling rather sleepy. ;-)