Intruder alert!

       Extermination - nigh on impossible.  Lesser Celandine = Greater nuisance.  I have yet to check if the Greater Celandine is even in the same Genus(?) I remember being instructed to rub Greater Celandine (Orange coloured) Sap on my Wart as a cure. NOT a clue if it worked - BUT I haven't had a wart in decades.    ;¬ )   
       If you're unfamiliar, they have a series of tiny little bulbils underground, most less than a Lentil - BUT - one missed = one total NEW plant. 

I'll just nip off and check, while it's fresh.

EEEEK! As some have been heard to remark -"Who KNEW?"
I found thus:-
"There are three plants with yellow flowers called celandine in the British Isles: the Greater Celandine (Chelidonium majus), the Lesser Celandine (Ranunculus ficaria), and the Celandine Poppy (Stylophorum diphyllum)."