on a topsoil heap on OU campus. Roy Maycock the county plant recorder did ID this for me but unfortunately I mislaid the answer.
No interactions present.
Looks like a young Black Nightshade (Solanum nigrum)but not at all sure. Black Nightshade is usually hairless but there are varied types.
Green Nightshade is similar except for fruit colour.
I cannot think of any other likely native or naturalized species.
Might be the green as this is hairy, certainly not black.
Perhaps this is a untypical cultivar of potato
Lat/Lng: 52.023418, -0.707492
OS grid ref: SP887368