monkeyflower on the canal

I first saw the small monkeyflower plants along a wet area of the Regent's Canal towpath: the gutter at the base of the wall where it's green from the plants self-seeding there. View from St Pancras Way bridge over the canal.

While walking along St Pancras Way and looking over the canal, I noticed a monkeyflower had self-seeded there on the pavement.

a close-up of that seedling

after seeing the monkeyflowers on that section of the canal, I noticed some by one of the locks near me (Hawley Lock)

and another younger one without that distinctive 3rd or subsequent leaf