Plant ID

[ElasticFirecracker]

This started growing a couple of months ago, it has sort of maple-y leaves. I thought it was a weed and was just about to pull it up, but then saw it was flowering.

Is it a weed? Does anybody know what it is?

Shoo-fly, Nicandra physaloides. Not a british native.

Only you can tell if it's a weed - a weed is merely a plant where you don't want it to be. Something can be a weed in one place (like the forget-me-nots covering my terrace) and a treasured plant in another. The main seed suppliers sell seeds of shoo-fly. Also called Apple of Peru. Srah Raven describes it as a tip-top garden filler and cut flower.

@MereDintofPandiculation thank you so much, that's really interesting. I'll just leave it and see what happens to it.