Solved Which plant is this?

Hello, this plant has sprung up in several places in my garden. I'd like to know its name so that I can check what it grows into and manage it accordingly. (I mean the three tallest plants, in the picture.) Thank you in advance!

 

I think it is a Euphorbia but others will know for sure.

 

Hello,

Those are caper spurge, Euphorbia lathyris. Some people use it as an architectural ornamental plant, but to others it's a non-native weed. I've got one filling a space in my new dry bed while the smaller plants establish. Be careful of the white lac, as this is harmful, especially to eyes. Note that this is not the same as a 'caper'. This plant is definitely non-edible.

 

Great, thanks a lot to both of you.