"Flowers" of a mysterious tree at the river bank.

Hi Katarina, this looks vaguely familiar, but can't place it at the moment, are these the buds, or the actual flower?, I'll try to remember it, Derek.

nothing to add, need to add a comment to keep up with developments!

White Ash - Fraxinus americana ... ?
The small black buds (bottom right) and colour of the bark, are certainly characteristic of an Ash tree.

http://becuo.com/white-ash-flower

It was identified yesterday as Fraxinus Excelsior, the sort of European white ash.
Thank you for helping, Hywel.

Hi, Derek, lol, I didn t know it either, do not worry, but I was told yesterday that these are male flowers of European ash tree just before their opening (blooming). So, well timed, I can´t help :-)