Can anybody solve this mystery?

[Primrose]

This year I've tried growing cape gooseberries from what I think may have been a free KG seed packet. I only got 2 viable plants which I planted out.
One is bearing fruit. The other plant, which in its early stages looked similar, has grown into something three times the size of the cape gooseberry plant and has a pale mauve/blue flower.
What could it be? I'm mystified.

[Geoff]

You may have Shoo_Fly https://www.rhs.org.uk/advice/profile?PID=538

[Primrose]

Thank you Geoff. That,s a possibility. I left the tray of seedlings out In the garden before planting out and I suppose its possible something from a bird feeder somehow got mixed in with it, although I was sure the seedling might have emanated from the seed packet. It seems this Plant does produce similar berries to the cape gooseberry although I have n,t seen any fruit forming on it as yet after the flowers have died back.

[sally wright]

Dear Primrose,
DO NOT eat the fruit! It is probably toxic. This is a hard rule when dealing with the potato/tomato family of plants. Do not eat any of them unless you KNOW FOR SURE they are edible AND also which parts of the plants are the edible bits as well.
Regards Sally Wright.

[Primrose]

Sally, thank you for the warning. When the mystery Plant was smaller it very much resembled the other cape gooseberry Plant before the growth suddenly started taking off. As yet I have seen no berries foeming but will pull it up to avoid any potential accidents happen8ng, although I think Inwould have been wary anyway given that the plants in maturity now seem rather different.

[PLUMPUDDING]

It says the Shoo fly is usually grown as an ornamental, most parts are toxic, and some people rub it on their skin as an Insect repellant in its native Peru. It is also said to repel white fly if planted near susceptible plants. It looks nice but sounds a bit dodgy to handle. Surprisingly they put it in bird seed mixes so the seeds must be ok for birds.