Enchanter's Nightshade runs by white roots underground, rather like ground elder. Make sure you get all the bits of root or it will be back!
Geranium robertianum spreads by self-seeding. I have it all over the place, but I don't mind because it is a native wild flower of shady and damp places and a very pretty one too. It is very easy to pull out if you really don't want it where it is.
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2. Could be Herb Robert, geranium something, weed / wild flower.
When you don't even know who's in the team
S.Yorkshire/Derbyshire border