Unidentified wildflower - can you?

Spotted near Sudbury Hill, Harrow (18/10/2023)

The single flower is small but not tiny with four petals and inner layer of petals emerging. The petals are magenta with darker stripes a bit like Common Mallow and the leaves are oblong densely veined and with finely jagged edges. So far the Plantnet app and RHS online have failed to match this plant with any other. [It must be rare, no? Ed.]

Update

The same plant two days later (20/10/2023)

The flower has opened out and looks a bit different. Thanks to Anonymous for the comment below, which seems to have solved the mystery. Quote: "It looks like an Annual Clary (also known as Red Topped Sage) to me. Usually found around the Mediterranean and not Willesden Green." Of all our millions of readers, Anonymous was the first to come up with a sage answer to the query. [Ed.]