In message , K
writes
Stewart Robert Hinsley writes
The number of stamens is wrong for a Lysimachia (compare creeping
jenny and yellow pimpernel) as well.

And the leaves look too fleshy. It may be me misreading the pic, but
the leaves seem to be of similar fleshiness to ivy-leaved toadflax - is
that impression right? - it's certainly more the fleshiness that you'd
associate with some of the saxifrages.

I'd say that the leaves are fleshier than Cymbalaria, but then I don't
find the leaves of Cymbalaria to be particularly fleshy. (But they're
variable; the local stately home has a population which is less
trailing, with fleshier leaves, than those I've seen growing wild.)

But now that you mention toadflax and saxifrage, I open Stace, and find
a decription of Celandine Saxifrage (Saxifraga cymbalaria), which is
what it appears to be. (Now I look at the photograph of the flower I see
that it does have a second carpel, which I had overlooked, causing me to
discount somewhat Saxifragaceae.)

So, thanks - you nudged me in the right direction.
--
Stewart Robert Hinsley