Answer:
I am the place to turn when nature calls.
Though not a plant I have leaves. though not a beast I have spine. Though many wouldn't need me I am more valuable than wine.
the only amusing part of the body
I get thrown in the air and will fall down. I get thrown down and I will rise in the air. What am I?
From house to house I go, sometimes narrow, sometimes wide. Whether there's rain or snow, I always stay outside. What am I?
No matter how little or how much you use me, you change me every month.