Answer:
Plant whose name sounds like a dish full of dairy spread.
Many hear me, but no one sees me, and I only speak when spoken to
What is as big as you are and yet does not weight anything?
Ten men's strength, ten men's length. Ten men can't break it, yet a young boy walks off with it.
To cross the water I'm the way, for water I'm above. I touch it not and, truth to say, I neither swim nor move.
You use it between your head and your toes, the more it works the thinner it grows.