Plant identification please

[Igneococcus]

This plant has grown in my curcurbits bed in the allotment (in a polytunnel). It's tall, at least 5 foot high. Does anybody know what it is? I hope the flowers will be open when I get back there tomorrow which should help with identification.
Any suggestions? Thanks.

[chemenger]

It's a triffid.

[Igneococcus]

Might well be chemenger
We do have a climbing winter squash in another bed which I suspect has plans of world domination, it's enormous.

[Igneococcus]

I think it's Datura stramonium and it's highly poisonous. I have no idea how it got into that bed.

[Trethew]

Agree it does look like a Datura but don't know. Don't Datura flowers hang down? Could it be henbane? As you say, it will be easier to id when the flowers open.

Many commercially available seeds are grown under contract in hotter countries, where two or three cycles of sowing and harvesting are possible in one year. Maybe a rogue seed slipped through the cleaning process into your seed packet.

[Igneococcus]

This is a picture I took today. It looks just like the flowers of jimsonweed I found on google.
Everything in this bed is a cucurbit, melons, cucumber, courgette, tromboncinos, their seeds look quite different. There are some marigolds as well (to encourage pollinators into the tunnel) maybe the seed was in there.
We'll take it out tomorrow. There are often children in the tunnel, very well behaved usually, but datura is just a bit too poisonous to take a risk.

[Trethew]

Yep, that's a Datura. I'd remove it pronto, especially as it's in a tunnel full of edibles.

[Bolshybookworm]

Definitely a datura. I think thorn apple is naturalised in parts of the uk, so it may not have come from a packet of seeds but from a bird or the soil.

[Igneococcus]

I'll take it out tomorrow morning.
The seed might have been in there for a while and been dormant. We put seaweed on the beds during winter and some of our compost from home. Birds sometimes get into the tunnel so it could have come in with one of them.