grows profusely in my garden;
No interactions present.
... so the appressed fruits of this plant excludes these.
The small flowers would make it Sisymbrium officinale rather than Brassica nigra or Hirschfeldia.
Sisymbrium is heterphyllous; the leaves are different on the various parts of the plant, which can cause confusion if the basal leaves have been lost (I confused S. orientale for S. altissimum once because of this.) The foliage does look a bit off (but perhaps I'm confused by only seeing leaves from one part of the plant) but no other Sisymbrium has appressed fruits.
... had been offered for the two photograph. I agree that there might well be two different plants here.
Lat/Lng: 50.8, -0.1
OS grid ref: TQ3603