Okay, I admit to it: as of now I have no idea what tree exactly this one here is. Which bothers me.
I'll try and find out a.s.a.p.
Ah ... gotcha!! You are Acer negundo - Eschen-Ahorn (Maple Ash), and those flowers are male flowers. And the tree is not native to Europe, it is an immigrant from America, an invasive one at that. Planted in Central Europe since the 17th century already. I haven't seen one of those in Mühlviertel, and I am sure that none grow wild there - here in and around Vienna though they are not uncommon. And their flowers do look nice, don't they?