Most definitely agreed they are not just for water just typical reflections - I should have made sure I wasn't trying to argue that from start when I spoke of reflections.
Haze is in fact reflections from particles in the air (which comes back to that "everything is a reflection" point in my last post). The polarizer is helping to remove those and give you that pop. It's the same for greener or more colorful/saturated foliage. As the polarizer is adjusted to filter the light you don't want, you see the truer color of the plants more intensely.
Polarizers also make a great neutral density filter in a pinch and I have used them that way on occasion when I didn't have a proper one available.
I like that shot in your other post - I remember seeing that!
~Micheal
