Ivy-leafed TOADFLAX : Cymbalaria muralis
Also called Kenilworth ivy.
Ivy-leaved toadflax is not a native species to the UK, but is now considered naturalised, having been here for several hundred years.
It is a small, perennial herb that is often found growing in cracks in stone walls and has become a familiar sight around West Dunbartonshire.
Look closely and you will notice that its tiny, mauve flowers with white and yellow bulges resemble those of a snapdragon. It has reddish stems.
RHS : https://www.rhs.org.uk/plants/57492/cymbalaria-muralis/details
WIKIPEDIA : https://en.wikipedia.org/wiki/Cymbalaria_muralis
WILDLIFE TRUSTS : https://www.wildlifetrusts.org/wildlife-explorer/wildflowers/ivy-leaved-toadflax