I really like that photo! As you probably know, we call those buttercups here. I think they are beautiful.
I love them too, they have such glossy petals. In the German name they have the word "butter" in it too. I picked a little bouquet and ended up with yellow shoes.
Oh they are buttercups, that is what I thought! As children, we used to pick them and hold them underneath someone's chin to see if they liked butter (if their chin reflected yellow, they did)! We don't have buttercups in TX, too hot. We had them in upstate NY -- they have similar climate to Germany, tho I think lots colder for longer. Love your shoe pic!