No interactions present.
This has greenish flowers, I don't think you would confuse them. The dark marks on the leaves of P. maculosa are also a useful clue.
... can have white flowers and scarcely marked leaves, so it may be possible to overlook Persicaria lapathifolia as the former (I've remarkably few records of the latter) or mistake a pale-flowered scarcely marker plant as the latter (I did that several years ago when I was less experienced), but this there's no doubt that this plant is Persicaria maculosa.
I don't agree they can be mistaken on the basis of those characters, this is why other characters are used in good keys such as Stace's. It is more 'likely' to be P mac. but it 'might' be P lap as well.
Lat/Lng: 55.089, -6.051
OS grid ref: NW416846