K wrote:
Leaves are wrong for a Geum, surely? Geum leaves have pinnately arranged
serrated lobes. The leaves of the plant in the question are deeply
divide palmately arranged lobes.
I'd agree the petals are from the aquilegia. Perhaps La Puce is thinking
that the lobed leaves are geranium rather than belonging to the yellow
flower? - they are similar to geranium leaves but not quite right.

Indeed. In my garden, flowers grow through other plants and give the
impression that a flower, say marguerite, would belong to the fatsia
leaves because it is growing through it. I like this very much )

Here is the blue geranium in my garden. The leaves are very similar to
the OP's picture.

http://cjoint.com/?giltf6kFT8

This is the Johnson's one, which I would like one day .... :

http://cjoint.com/?gill7bu6iX

And here is the yellow geum. My geum is red but start yellow and keeps
a yellow rim on the red petals. I'm really happy about this as I
thought I had a yellow and was very dissapointed. Anyhow the leaves are
very much like the one on the OP picture. And the flower is indeed like
the ronunculus ones - buttercup family - like the geum.

http://cjoint.com/?gilmBToGnZ