Can anyone help identify this plant?

[fourplusfour]

As the title says really. A prolific grower and had lots of cuttings from it but cant remember what it's called.

Don’t recognise it but the flower form suggests Lysimachia

The flowers do... my app says Lysimachia congestiflora but the leaves don't look similar to me. Leaves look like my sedum.

Possibly Lysimachia Midnight Sun.

Thanks everyone. Just done a Google image search which seems to agree.

This app is pretty handy candide.com/GB/identify-plants