Answer:
Runs smoother than any rhyme, loves to fall but cannot climb!
It stands upright and can be quite grand. Its secret is not hidden but right at hand. What is it?
I grow for a surface, even if you cut me. I continue to grow even after death.
The moon is my father. The sea is my mother. I have a million brothers. I die when I reach land
Walk on the living, they don't even mumble. Walk on the dead, they mutter and grumble.
If itβs information you seek, come and see me. If itβs pairs of letters you need, I have consecutively three. What am I?