flowering in a french rock garden

Need a better photograph, close up of flower and leaf, but have a look at Melilotus officinalis as a possible...

yeah, Bamboo, it could be that, but the leaves seem wider and the flower is cream rather than yellow - it's flourishing - perhaps too much - in my rock garden but once again the bees love it... and presumably the lady before me tried to grow it 'cos as I mentioned there's a patch further down in shade under my mature oak and pine trees.

I'll try and climb up (rock garden bed is nearly inaccessible for photos, to my somewhat crocky knees at least!) to take a better pic...

That'd be good - the sunshine on the flowers, and the distance away, means you can't see them or the leaves properly... but don't break a leg, its probably not worth it!