I'm confused with this plant, the flowers do look like Lysimachia, but the leaves don't fit any species I have googled.
http://www.google.be/search?q=....
The flowers do look very much like Lysimachia punctata, but that one has smaller and neat leaves, and the flower whirls are much closer together than in mine. The leaves on mine are very big and don't look as neat as any other lysimachia.
I think I found the plant in the nature reserve..the picture dates from 30th May 2009.